Its puppet sex. And is basically every porn movie (in terms of positions) ever made. The audience laughed so long watching it.
If you didn't stay for the last, last, song in the credits, you missed a wonderful "homage" to Alec Baldwin that wasn't in the movie. My sides still hurt. BTW, there was a much older crowd in the matinee and the laughing was uproarious. It's a total send-up of Hollyweird leftists. Trey Parker is BRUTAL on Hollywood.
If we're in a culture war, then Trey Parker has taken up the rough and crude weapons of mass hilarity in order to make a point. Like any war, it ain't pretty...but it sure is satisfying to win.