The heat of the coffee will kill the man's sperm immediately. The loose skin of the scrotum lets a man's balls hang away from his body so their temperature is slightly less than body temperature.
she obviously didn't drink the cum or else they wouldn't have cut away and then showed her again drinking from a cup but not letting you see what's in it. they couldn't just get her to drink the cum?
I bet she was in the girl guides, ever the resourceful.