When the female is lying naked on her back and the male riding a broomstick charges into her, shoving the broom up her butt while screaming "FOR GRYFFINDOR!"
Example 1: I gave my girl a Harry Pooper once and now anytime she hears the Harry Potter theme music she clenches up while yelling “No Hagrid, NO!
Example 2: I refused to tell my boyfriend that "he’s a wizard" during sex so while I was sleeping he gave me a Harry Pooper...I still have splinters.
Someone who jumps from one relationship immediately into another one.
Serial monogamists can not stand to be alone and often suffer from vast commitment and insecurity issues.
Because they jump into relationships immediately after the previous one has ended, serial monogamists typically don't take the time to reflect on their behavior or why their previous relationships failed; thus, they end up making the same relationship mistakes over and over again.
Person 1: Damn, Dustin already has a new girlfriend?! It's only been two weeks since he broke up with his fiance! I think he's a sociopath.