When someone you have had sex with in the past shows up or are friends with someone you want to have sex with in the future, they are a poontangboomerang.
"Dude! I went to a party with my new girl , and her skank friend showed up that I was down and dirty with the night before! That girl is a poontangboomerang !"
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi