There was an episode of the Brady Bunch where some rival of Greg's was dating Marsha. Greg was certain that the guy had ulterior motives, but Marsha dated him anyway.
Greg and his brothers made up a phony playbook for the guy to steal, which he did.
When Mike (the father) found out about it, he insisted they tell the other team the playbook was phony. As I recall they didn't believe him, and Greg's team won convincingly.
I think Marsha broke up with the guy or maybe he lost interest in her after the game was over.