Spank Bubble

The subject of one's sexual fantasy during masturbation, usually had by someone with a penis that he can "spank."

Sometimes referred to as "Spank Tank."

"You think about that girl all the time, she's totally your spank bubble."

or

"That girl is hot. I'm gonna make her a part of my next spank bubble."

by Oracularecho January 14, 2009