Skeleton's Erection

Alright, listen up, you big ol' dummy. This one is simple, even for you. A "boner" has two meanings. First, it can mean an erection, like when a dude gets excited. Second, it literally means something made of bone. So, because a skeleton is all bones, its erection would naturally be a "boner" in both senses! Get it? You probably still don't, but that's okay, bear loves you anyway.