Positive Reinforcement

"Have you ever seen a sword swallowing act before?" she asked him.

"I think I've seen a clip of one before, yeah."

"Well, for the ones who actually do it and don't just use a rigged prop, normally they have to face upwards so that the route from their mouth to their throat is one long straight line and not a curve like normal."

"So, what you're saying is..."

"I can swallow more of your sword this way," Nina finished with a cheeky grin.

"You're enjoying this aren't you?" Seth asked her, trying hard to supress a grin of his own.

"Just helping out however I can," Nina retorted. "Same rules as before, you need to push and to pull, ok?"

Seth nodded as Nina took a hold of his cock and leant her head off of the end of the bed, creating the 'straight line' she'd talked about. She stretched her jaw slightly before placing him back in her mouth. The familiar thumbs up told Seth to begin. He slowly pushed forward, gently but firmly using the sides of Nina's head for purchase. Feeling Nina's tongue on the opposite side of his cockhead now felt heavenly and he shuddered slightly as he continued his push forward. Nina seemed to be holding back her gag reflex even stronger than before as more and more of Seth's cock disappeared into her. They were definitely past the point they'd been at before, but Seth was starting to feel more resistance and stopped his advance to pull back and pull out.

Nina gasped for air slightly but looked a little annoyed.

"What did you stop for? We were doing great!"

"Sorry, I hit a bit of resistance and didn't want to hurt you," he tried to explain, but Nina was having none of it.

"Do you want to cum or not? Stop worrying about it and just fuck my throat already!"

Seth was slightly taken aback by Nina's bluntness this time. She must have sensed this and tried to compose herself.

"By which I mean, I'm fine, thanks for your concern. But you need to be less hesitant if this is going to work, ok?"

"Ok, ok. But please tell me to stop if it's getting too much? I want this gone but it's not worth hurting you for."

Nina felt surprisingly touched. She forced herself to move past this and get back on track.

"Of course, scouts honour. Now, back in please," she grinned.

Seth moved back closer to Nina and allowed her to position him back in her mouth. As before he slowly pushed forward bit by bit, enjoying every little movement, until he hit that area of resistance again. He stopped whilst he considered what he was about to do and sensing his hesitance, Nina gave him one more thumbs up. With that, he pushed hard forward.

Nina jumped as all at once all of the cock already in her mouth suddenly jumped down her throat. She could feel it stretching her oesophagus past the size it should naturally have been but instead of the pain she was expecting, it actually felt amazing. She didn't know if it was shock or desire or a combination of the two, but she wasn't about to complain about not feeling any pain.

Seth was practically stuck in place with both shock and desire himself. As he'd pushed in, he'd watched in awe as he could physically see his monstrous cock pushing out beneath the skin of Nina's throat, creating an outline of it. He could feel her throat muscles contracting and spasming around his cock as her body tried desperately to react to what was happening. There was definitely another reaction happening, however.

Seth noticed that Nina had started to writhe and shake all over her body and she was moaning as much as her blocked throat would allow. Worried she might be having a fit, he started to pull back out but stopped when he saw her hand shoot up and frantically wave as if to tell him 'no!'. So instead he continued to watch as she moaned and spasmed around his cock for another couple of minutes until she finally stopped and seemed to allow him to pull out.

"Are you ok Nina?" he asked, both perplexed and concerned.

"Oh yeah," she gasped, "I'm more than alright."

The realisation hit Seth like a truck.

"Did... did you just cum from that?"

Hearing himself asking Nina those words felt really strange, but equally Seth was eager to know.

"Baby I've came before but THAT was something else entirely!" she laughed still trying to catch her breath.

Seth was frozen; had she just called him 'baby'?

"But I notice you still haven't blown your load yet. God damn that stuff is potent! We're running out of options here!"

As far as Seth could tell, there was only really one option left and it was the one thing he had resisted the whole time: they had to have sex.

Nina could tell the cogs were whirring in Seth's mind. Even after what they had just done, he still was having trouble accepting what had to be done next. Frankly, she was now more invested than ever in making it happen. The orgasm she had just had from deepthroating Seth, even though it had been barely half of his currently length, was easily the most intense of her life. She'd done it with a couple of guys before but none of them had elicited that kind of reaction and certainly she'd never cum from just sucking a guy's dick before. Whilst she was almost certain the sheer size and inherent naughtiness of what she was doing played into it, she couldn't help but think that maybe the fact that it was Seth she was doing it with was the main factor? After all, she was never as relaxed as when she was with him. Perhaps that was why it hadn't hurt? She had so many questions but for now she needed to help Seth answer his own.

"I can tell what you're thinking Seth. You know what my answer will be if you ask, but you have to ask."

"There's so many reasons not to, Nina..."

"Name them."

Seth stopped for a moment, composing his thoughts.

"Once we've crossed this line, there's no going back. I know you said before that it doesn't matter Nina, but it does to me. What if we get to the other side of this and we just can't come back to what we have?"

"You just made me cum by shoving your cock down my throat, I think we're past the line quite frankly," she tried to joke.

"Please take this seriously Nina..."

"I am taking it seriously. To be honest with you, Seth, I don't like the idea of someone else being the one to 'help' you with this. I know we're just friends, we're not boyfriend and girlfriend or anything, but I feel responsible for this and I want to be the one to put it right. Ok?"

"Is that all you feel?"

Both of them were stumped by what Seth had just said. Neither of them had ever been confronted by their potential feelings for one another, especially not in front of one another.

"I... I think that's a question that needs to be answered. But not right now," Nina said, trying to divert the course back to where it needed to be. "Right now, we need to deal with that. So, ask me."

For once, Seth had to admit that Nina was right. It was a question that needed an answer but there were far more pressing matters at hand. If it wasn't going to mean anything to her, then Seth supposed that asking her to do one more thing to help him out of this mess was the last step he had to take. He took a deep breath.

"Nina. Will you let me have sex with you?"

"Hell yeah!" she smiled.

It felt like a large weight had been lifted from Seth's shoulders. He watched as his closest friend and now his one-off lover removed the last of her clothing and smiled contently.

"Jeez, these things are soaked!" laughed Nina as she removed her underwear and waggled it front of Seth before casually throwing them to the floor. "Should mean I'm nice and ready for you though..." she continued with a sultry grin.

"Are you sure? I mean this thing is pretty big..." Seth replied, starting to feel his inhibitions trickle away.

"So big! The biggest I've ever seen! I had no idea," Nina giggled, thrilled that Seth was finally letting loose.

"All your fault," he grinned as he started to mount the bed.

"You mean I made it that big?" Nina asked innocently as she moved herself up the bed away from Seth and opened her legs in anticipation.

"Your beautiful face, your huge tits, your amazing ass; how could I not be this big for you?"

Seth's inhibitions were all but gone. More importantly, that memory that had haunted him all these years was nowhere to be seen. All Nina could see now was pure desire in his face, desire for her. For a moment, she was willing to forget the mistake that led them here, that caused his sudden enlargement, and let herself believe that what he was saying was true: he was so big and so hard right now because he found her so damn hot.

"I hope my pussy isn't too tight for you," she breathed as she stared him dead in the eyes.

"Only one way to find out," he replied as he reached down and positioned his cock just outside of her velvety lips.

"Just give me as much as you can, you won't hurt me," Nina told him with a slight beg in her voice.

"All in good time," he replied with a grin.

This was it. He was about to have sex with his oldest, closest friend. His beautiful, amazing, incredibly hot friend.

With a slight grunt, Seth pushed forward and felt his cock slip unrestricted into the warm, tight recesses of Nina's pussy. Nina howled as more cock than she had ever felt stretched out her insides.

"Oh fuck baby! Fuck! It's so fucking big, I can't believe it's in there! It's stretching me out so good!"

"You think you can take more? That's just the tip, sweetheart, I've got way more to give you!"

"Oh yes, fuck yes, I want as much of it as you can fit in me!"

Seth listened to Nina's pleas intently and started to slowly thrust back and forth, pushing in hard with each stroke before pulling out gently, more and more, inch after inch continuing to disappear inside Nina as he did. Nina moaned and squeaked with each thrust, slowly feeling herself getting fuller and fuller with each stroke of Seth's monster cock.

"Oh fuck! I can fucking see it!" she cried.

Seth looked at her stomach and just like with her throat could see the bulging outline of his obscene cock stretching and distending the skin of her normally flat belly, coming and going with each thrust. The sight must have been too much for Nina to take as Seth began to feel her shake like she had before.

"You gonna cum for me sweetheart? You like seeing this massive cock stretch you out?"

All Nina could manage was a nod and a whimper as her orgasm skyrocketed towards her. When it hit, her whole body went into overdrive and she began wildly bucking back against Seth who simply basked in the moment.

"Yes, yes, yes!!! Fuck me so good! I'm cumming, oh god, it's so fucking much!!"

Nina wasn't lying. Seth felt a spray of hot liquid on his chest and looked down to see that Nina was squirting with a huge amount of force all over him. Seth knew it was something that could happen, but he neither ever expected to experience it or thought it would turn him on so much. He watched in awe as Nina finally started to come down from the incredible peak she'd been at.

"Oh my god, Seth," she panted. "Please, please tell me you've cum?"

In all the furore of the moment, Seth hadn't even realised that he still had not cum. With a worried look, he shook his head.

"Man, what is it going to take big boy?" she smiled at him.

"Genuinely, I'm a little lost," he said with a confused smile of his own.

"Well, you've fucked my throat, you've fucked my pussy, I think that leaves only one thing..." Nina said with a wicked smile.

"Are you sure? I mean your pussy was one thing, God knows how I haven't damaged you there, but your asshole? I'll split you apart, literally!"

"Oh I mean it'll need warming up sure, it did for ones less than a quarter of your size, but if we manage it, you might even be able to get deeper than my pussy. Maybe that's what's wrong! I haven't taken enough of you yet!"

Seth laughed and made up his mind.

"Ok then Nina. Let's get you warmed up..."

Seth started by running his fingers up and down Nina's soaked pussy, covering his fingers with as much of her natural lubricant as possible. Her asshole looked so small and tight like it had never even been breached before despite Nina's claims. Seth carefully worked his index finger around the outside of her puckering ring in circular motions until he was able to just slip right inside. He pushed his finger up to the knuckle in her tight hole as she gave a small little gasp and smiled contently. After a few moments of gently rotating his finger in small, circular motions inside her, he pushed in a second finger and marvelled at how pliant she already was. He pulled his out and back in in small, repetitive motions that almost mirrored his performance in her pussy earlier.

"Mmmm, I don't think I've ever told you this but I love my asshole being played with," Nina purred at Seth.

With that admission, Seth added a third finger and started to spread his fingers slightly as he pulled out of her before diving back in again. From what Seth had seen online, he should have needed copious amounts of lube to be able to do this, but he was sliding in and out of Nina's asshole as easily as if it was her stretched pussy, almost as if her body wanted him to be able to enter her asshole. Nina was breathing more and more heavily, the way she did when she was starting to really enjoy herself as Seth now knew.

"I don't think I can wait much longer Seth, I need that cock back in me," she moaned.

"I'm only up to three fingers, are you..."

"I'm so fucking sure Seth. I want you in me now."

Yet another offer he couldn't refuse. Taking matters into her own hands, Nina had already gotten herself onto all fours and reached for Seth's cock, which she was guiding straight to her waiting asshole. She pushed back slightly and Seth watched with amazement as her tight little asshole opened wide to receive his enormous cock.

"Oh fuck! It feels even bigger in my ass!" Nina cried.

She felt Seth place his hands either side of her hips. Despite the railing she knew she was about to get, she somehow felt safe and secure, as if this was meant to be. She turned to look over her shoulder and met his gaze.

"Fuck my ass Seth," she commanded him.

Seth's grip tightened as he pushed hard into Nina. Unbelievably, half of his cock entered her straight away and she let out a guttural moan. He could have stopped there, but she'd told him to fuck her and that's exactly what he was going to do. His cock felt like it was encased in a warm, velvety vice as he felt her asshole squeeze and contract around him as it tried to get used to this oversized invader. He pulled out slightly and then rammed back harder than he'd dared before, a little more of his cock sliding inside her which thrust. Nina started to push back in time with his thrusts, pushing him even deeper, clapping her ass cheeks together and drawing intense moans from her.

"Oh my god Seth, you're so fucking deep, so deep in my ass..."

"Just a little more, Nina, god you're so fucking tight! I never want to leave your ass!"

"It's yours, baby, it's yours! Whenever you want!"

"I'll always want this ass, Nina, I'll always want you!"

"Then you can have me Seth! Fuck, you can have me, I'm all yours!"

"I love you Nina!" Seth cried out.

Without a seconds hesitation, Nina replied.

"I love you too Seth, so fucking much!"

With that declaration, Seth made one last huge push and bottomed out in Nina. They both cried out in pleasure as they jointly experienced more than any human should have been able to. Seth's eyes suddenly shot open as started to feel the sensation he'd been desiring for so long shoot up his cock.

"I'm gonna cum, Nina, fuck!" he cried.

She pushed back and bucked on his cock for all she was worth.

"Cum for me baby, please cum, I want you to cum in my ass, fill my ass up with your cum!" she begged him.

With a final slam of his hips against her ass cheeks, Seth came. Nina shook all over as once again her body burst into orgasm. She could feel Seth's cock swelling and contracting with each burst of cum and could even feel his hot seed blasting against her insides. More and more kept shooting out of him, filling up any part of her his cock wasn't already occupying, until finally it was over.

The two of them collapsed side by side on the bed, Seth's cock still very firmly wedged deep into Nina's ass but slowly starting to deflate, hopefully back to normal. As they lay panting, he tried to make sense of what had just happened. Before he could speak, Nina beat him to it.

"I guess the 'release' you needed wasn't just to cum then," she said in a light tone.

A little concerned at how out of hand everything had gotten, Seth tried to speak but Nina cut him off again.

"I know what you're going to say Seth. That head of yours will be worrying about every tiny detail right now. But I meant what I said. I'm yours if you will have me. I love you."

Seth was speechless. Nina reached around for his arm and pulled it across her chest, letting it rest lightly on her breasts.

"I love you too," Seth whispered in her ear.

"I know you do," she smiled. "And ha ha, you're touching my boobs now."

Seth smiled at the playful grin on Nina's face. He nestled into her shoulder and kissed her tenderly on the neck.