Mmmm. Kind of late, but I'll chime in. My sex life, other than tickling pretty girls, is pretty staid. I do, however, have a very active fantasy life. Some of it I've tried, but the majority will stay fantasy.
It's said that everyone wonders what sex would be like for the opposite gender. I'm male, but 90% of my fantasies are from the female point of view. I have no desire to live life as a female, or get a sex change, or any such thing. It's just that the female point of view of sex turns me on. I'm always very considerate of my lovers. Oh, also, I'd like to give a blowjob someday but other than that I'm straight.
So with the disclamer that everything below is meant with me being in the female point of view unless specifically labelled as for either gender...
A lot different loss of control situations, most of which have been mentioned by others. Urophilia (that is, holding pee in until you lose control, or being tickled until you pee), both sides of tickling in either gender (only if it's sexual if I'm watching a male ticklee), riding the edge of orgasm or teasing and denial for either gender (so long as the teased cums at some distant point, otherwise it's just torture).
Bondage plays a part in the majority of my fantasies, or being in a position where one (either gender) is helpless. That's how tickling does it for me- it's the helplessness of the ticklee that really gets to me, with the forced laughter just being a demonstration of the helplessness. BDSM, but there are very firm bounderies. I don't like pain or torture, but spanking or whipping is allowed in order to tenderize skin for later pleasure. Also, spanking as a show of dominance, so long as it's not too painful.
Enema play, where the girl is filled to the edge of pain. I've also had similar fantasies about filling the bladder in the same way. Both of these situations depend on me being in the female role in particular, since watching someone else on the edge of suffering doesn't do anything for me (I've tried).
Telling a girl in bondage that she has somehow lost her birth control and having her worry and beg to cum outside of her (which never happens). But even in my fantasies, she's actually safe from pregnancy. The idea of actually tieing someone down and impregnating her against her will is abhorrent, but the threat really does it for me.