Definitions by SasquatchSB

Knucklebutting

The act of inserting multiple fingers at least second knuckle deep into your partners rectum, optimally by surprise. Often done during fellatio or cunnilingus.

Sabrina is great at knucklebutting, she can get third knuckle deep before you even notice.

Knucklebutting by SasquatchSB October 5, 2010