I wouldn't say the sex with my ex was mind-blowing, but a couple things stand out in my mind that creeped me out a bit:
1) Her eyes would roll up into her head fairly frequently.
2) Occasionally after sex the ex would blankly stare up at the ceiling. I'd snap her out of it, "whats wrong, babe?". She'd cry a bit and tell me she didn't know but felt "homesick", would want to cuddle and "crawl inside of me."
Always enjoyed the cuddling, drew the line at crawling inside of me (I'd always picture Luke slicing open the Tauntaun and crawling in).
Weird stuff, she denied ever being sexually abused by a family member but I am convinced otherwise.