spank bank

plural spank banks

1. slangA mental stock of images or fantasies brought to mind when masturbating.

   Now my mother just became part of his spank bank. Just what I needed. The only guy I was screwing and now when he was whacking off he'd be thinking about my mom. Ick!

   2005, Jill L. Ferguson, Sometimes Art Can't Save You, In Your Face Ink LLC, →ISBN, page 22

   2 more examples

   […] but on the other hand it would've been nice to get a view of that outstanding cleavage again. It was a thing of beauty and had immediately qualified her for membership to my mental “spank bank.”

   2007, Brandon Wilkinson, Memoirs of the Messed Up Minds, iUniverse, →ISBN

   The Highwayman Fantasy had been in the spank bank forever. When she watched old episodes of Star Trek, she'd wished for the holodeck to be real so she could be held up and accosted by a handsome highwayman who was really a disinherited duke trying to right some horrible wrong, […]

   2012, Saranna DeWylde, How to Lose a Demon in 10 Days, Brava Books, →ISBN

   Synonyms: wank bank