I guess it depends on the context, dirtiness, and the language, because I have a lot of contenders for each.
Off the top of my head, one of the hottest things that ever happened was with an Euphoria girlie who retired.
I had booked last call at like 9:30pm, which got delayed a good 30-45 minutes. I was in a forgiving mood, so I didn't cancel and dealt with it by pure luck in mid-February; I timed going to get a hot tea and coming back with them resolving whatever issue they had. When I got in, she was so apologetic that she gave me an everything-goes session (I really mean it) on her. We spoke her native tongue for the evening, as I had just finished my A-levels in it and have a penchant for it.
To make the deal sweater, what was supposed to be a 1h call went on for over 2h until the agency literally got pissed and called both our phones. We were just having too much fun to care about the clock. We cleaned up and then walked to the metro.
Aside from everything carnal that transpired, we realized we had a lot in common when it came to personality, intellect, and our social background, so she gave me her number. We never had sex again, but we did hang out a bunch until she left the country for an academic venture that same year.
Boyish looks do have their perks.