South Park: Season 3, Episode 8

3 - 8: Two Guys Naked in a Hot Tub

During the meteor shower, Stan's parents bring him to Mr. Mackey's party, but he is sent to the basement where he is forced to hang out with the dorky kids. He discovers that the ATF is surrounding the party, convinced there is a doomsday cult inside. Meanwhile Stan's dad and Kyle's dad share an intimate moment in the hot tub.