Really depends who it is. Someone like futasuck or pit sniffer is gonna be a nightmare. Unwashed, no deodorant and fat rolling in top of you struggling to breath. It would be a true nightmare.
I don't mean to jerk myself off but I've had lots of sex in my life and never had a complaint so it would probably be a better time than most of the fags here. I'm not fat, shower daily and I actually know what the fuck I'm doing.