7. Period Blood Girl's pants stain, Superbad (2007)
Superbad is one of the funniest Hollywood comedies of the past decade, but there is one scene that stops the whole thing dead in its tracks in revolting fashion. After Seth gets done dancing with a mystery girl at a party, he notices a red stain on his pants. It turns out that the girl was getting visited by her Aunt Flow pretty hard and heavy at the time and left an indelible mark on the impressionable youth.
This, of course, leads to Seth almost getting pounded into the pavement by the girl’s boyfriend, who also shares the same scarlet blotch on his pants. This is why you should only dance with girls who are wearing fisherman waders.