I've done collaborative sexual writing on and off since Yahoo! Chat had private user rooms. My tastes generally lie in two areas: more tame/vanilla versions of common extreme kinks, and kinks related to fanning or succumbing to desire. For example: Not torture and cruelty, but captivity, noncon stimulation/orgasm, mandatory submission, and light objectification. Not violent rape or hate-rape, but implacable claiming/use and trickery/betrayal. Not extreme ages, but naivety and acquiescence. Daddy/little girl or Mommy/dear son or bro/little sis, but desire- or genetics- driven incest. Not blood/gore and pain, but hymenal blood and vaginal stretching. Not humiliating/degrading cuckquean stories, but women getting off on watching/encouraging the fucking of another woman. Not public sex, but sex with the risk of discovery.