Ben's 'Mouse' is another word for his flat, hairy, no shafted, wrinkly ball-sack. In essence, Ben's mouse is not a penis, it's just a dangling sack in between your legs.
I can't believe I got sent a pic of Ben's mouse on Snapchat last night.
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