Example: Happy Days had an ep where the Fonz got engaged. They hired a stripper for the bachelor party, and she happened to be the stripper. They broke up.
Step by Step (or whatever the one wth Suzanne Summers was): The father's father got engaged to a younger woman. They hired a stripper for the bachelor party, and she happened to be the stripper. They broke up.
Absolutely, they can run out of ideas. Hence "the Simpsons did it" thing on South Park.