You start punching. Even with the gag, you can hear his pained screams as you pummel his genetelia, giving him twice the pain he gave you.

You keep punching untill his cock is spurting blood and his screams have subsided to whimpers. You continue your work, consuming him, whimpering at the pain as he streaches your throat and belly so tight you feel like you're going to burst. It's an impossible feat... But when you swallow the last of him, your belly is massively swollen. It hurts- but at the same time, the pleasure as he squirms inside you is immense.