Definitions by Fbook Masta

BSF 

Butt-Sex Friday, a time-honored tradition started originally as a joke in the CU that has grown into a near ritual. Simply put, Fridays are set aside for buttsex, feigned or real, and anal activity is less frowned upon.

Cam and Udara had mad BSF last week-Zhe

BSF by Fbook Masta August 13, 2006