I've never really been into roughness, but... Well, it'd be kind of interesting to slap somebody who really wanted it. Like, no harder than this, though.

I used to date a girl who would, like, BEG me to spit in her mouth. It was really effing hot.

There's really no better feeling in the world, IMO, than jacking off into an enthusiastic partner's mouth. Completely abandoning any inhibition, relaxing your pelvic floor muscles, looking at her (his, depending on your preferences) tongue, making eye contact, feeling the cum rising... Man, it's an incomparable feeling.