Its another name for closet sex.

The "Broom Room" part is closet (Since the broom is stored in a closet usually).
The "Womb Boom" part is sex.
If you put them together, its closet sex.
"What is "Broom Room Womb Boom"?

"It's when you have sex in the closet"

"Oh really? I lose my virginity that way."
by Henry Jakobsun July 6, 2009
Get the Broom Room Womb Boom mug.