dude i felt you swell up before [cumming] in that girl's [ass] we were cock knockin last night
when two guys are havin sex with the same girl at the same time vaginal and anal and they can feel each other inside her thru the thin membrane
"dude i felt you swell up before [cumming] in that girl's [ass] we were cock knockin last night" What is the definition of "cock knockin"?