It is when a boy is being sucked off, and as yoo eject the female keeps the penis fluids in her mouth, and forces it back in your penis by ridiculously hard blowing.
fred- hey man, i got a bastawank last night from this chick, her parent werent in,
bob - dude, you scored!
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