An act in which two or more women particpate in sexual intercourse in the scissor position.
"Dude last night in the shower those girls were totally knocking boxes."
by veevrede August 06, 2008
Another term for two or more ladies gettin it on.
Dude i swear my girlfriend and her best friend are knocking boxes they are always sleeping and showering together.
by bassfreek August 11, 2008