1. Figuratively meaning light, easy, care-free
play. Derived from pillow-fight-like play with beanbags. Mostly used to indicate the opposite. i.e. "ain't beanbag" means rough, cut-throat
play - especially in competition. This is used by a more mature audience.
2. Uncommonly used term for testicles
and scrotum. It doesn't take a genius or urban
dictionary to figure
out that connection.