Sleepy Sex with My Girlfriend?

This is my first story in a while. One reason for my absence is the desire to write longer, more detailed stories, and I haven't had time to do so. That's ironic because this one is short, though hopefully sweet.

My girlfriend Fran and I cuddled in bed. Fran is 45, with long black hair and a curvy body. Curvy in all of the right places, with gorgeous D cup breasts and a sexy butt - it reminds me of Shiv's butt on Succession. We both loved sex and made passionate love several times a week. But while I was really horny, I sensed that this wouldn't be one of those nights - Fran was tired and needed to get up early the next morning.

As we cuddled, we chatted about domestic issues. Specifically, she was worried about her daughter Karen. Karen was 19 and off for the summer after her first year of college. "I'm worried about Karen," she told me. "I think she may be sexually active. I really don't want her to ruin her future by getting pregnant."

Karen really had blossomed over the past year, going from a skinny teen to a sexy young woman. A younger version of her mom - not quite as curvy, but with perky B cup breasts and a nice ass, and the same long black hair. She was on the cross country team in high school, and had runner's legs. Lately she had taken to wearing almost nothing around the house - short boy shorts and tight crop top tee shirts with no bra. It was all that I could do to avoid staring at her firm young body as she paraded around the house.

"Why not get her started on birth control pills then," I asked.

Fran replied, "That feels like I would just be encouraging her to have sex. I don't want to do that."

"Babe, she's probably going to be sexually active whatever you do. Remember how you were." I didn't know her then, but Fran had regaled me with stories of her promiscuous younger years.

"I'll think about it," she said.

We continued to cuddle. I was spooning her, my cock against her glorious ass. I massaged her breasts, and rubbed my growing erection against her butt. "Not tonight babe, I'm exhausted and need to get up early." We drifted off to sleep.

I woke up as Fran was getting out of bed. I woke up with an erection. Fran smiled and gave my cock a couple of strokes, "tonight babe, I promise, I need to get to work now." She kissed me, and reminded me to get Karen up after I got up. I kissed Fran back, mumbled that I would wake up Karen, told her to have a good day, turned over and went back to sleep.

I woke up from an erotic dream about an hour later. Fran had returned and gotten back in bed with me. I was confused, as I knew that she should be at work. She had mounted me while I was still asleep - apparently my cock was hard from my dream. She was moving up and down on my cock, moaning. She was very wet.

I put my hands up and massaged her breasts. I was still woozy from sleep, but I noticed that she seemed lighter on me and her breasts smaller and firmer than normal.

I opened my eyes, and saw that it wasn't my girlfriend on top of me, but her daughter Karen. She was naked, her hair cascading over her shoulders. My hands were on her perky tits as she was bouncing up and down on my cock.

I exclaimed, "holy shit Karen, what the hell? I can't have sex with you - what would your mother think?"

She giggled, "you're already having sex with me silly. And I'm sure that she would be furious with both of us. But what mom doesn't know won't hurt her."

"No, Karen," I said, "get off me, we can't do this."

She replied, "like I said, we're already doing it. And I'm not getting off."

"But why Karen," I asked.

"Because I hear you fucking mom, and I hear her screaming and moaning about how good you are and how big your cock is. And she was right. And I also noticed the way that you look at me." I blushed; I guess my glances hadn't been as subtle as I thought.

She continued to ride me, and I continued to massage her perky breasts. "Yes, just like that, play with my breasts as I ride your big cock. It fills me up so good" I should have pushed her off, but her tight pussy felt so good on my cock. I thrust into her. I moved one hand from her breasts and rubbed her clit as she rode me. Soon she was cumming on my cock.

After she came down from her orgasm, she continued to ride me. I was getting close also. "Oh, god, I'm getting close. You aren't on birth control, are you Karen?"

She giggled again, "nope."

"What the fuck Karen, at least tell me that it's a safe time of the month."

She just smiled this time, "well I don't know, my period was finished two weeks ago. So I guess maybe I'm ovulating?"

Again I should have pulled out. But I was right on the edge,and before I could pull out I exploded inside her, filling her sweet young pussy with my cum.

We cuddled and kissed after that. She asked me, "isn't my young body better than my mom's old body? I just know that I'm a better fuck than mom."

"Don't disrespect your mother, young lady," I said. I continued to kiss her and massage her tight young ass.

"What will we tell your mother if you get pregnant?" I asked.

"I'll just tell her it was one of the boys at school."

As it turns out, she didn't get pregnant that first time. But fucking her every morning after her mom left for work, it wasn't long before she missed her period. Soon I'll be a father, and my girlfriend will be a grandmother.