Where the most sexually rewarding, explicit, fulfilling, and indulging recruiting sexual encounters and or memories are retained in the mind for the most anticipated and pleasurable masturbation sessions.

example1:

Logan : hey bro, remember when you and i ran the train on that 5 star DB  from Alabaster?

Nick: yeah man, i have that shizzle stored in my Spank Bank Safe Deposit Box

example2:

Larry: hey bud, did you end up hooking up with that horny, shredded DT that was all over you last night?

Kevin: Nahh dawgg, before we left to my place he passed out in the bathroom, i had to bring out old memories from my Spank Bank Safe Deposit Box that night as a pathetic attempt to even come close to the amount of pleasure that i was so close to getting..