After you have a quick session of anal sex with either a female or male, prefferably with female, and when you take out your whang from her butthole, you have a hard casing of poop on your dick
"I fucking just knocked my girlfriend up the ass, but when I took it out i had a fucking 'Hong-Long'"
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