Masturbelia
A cross of the words Masturbation and Memorabilia. Masturbelia can be anything, but usually is a personal object stolen from another person. The object is then used to masturbate while he or she fantasize about the person the item belongs to or reminds them of.
Dude! I totally stole a pair of Amy's panties to use as masturbelia. That chick is totally hot, and I would sell my soul to get a piece of that. The panties will have to do for now though.