When you squeeze together either sides of your chin and it creases.
This resembles a bum crack and it called a bum chin
This resembles a bum crack and it called a bum chin
by Gemmer September 02, 2006
you get your nasty girlfriend and stuff her in the butt, then proceed to use your shit-laden corn piece to have it away with her massively large chin bum until u cum all over her hidious face.
"oh man, that ugly bitch caroline gave me such a relentless bum chin wank i discharged all over the fucking show"
by marcus clefticus March 06, 2008