A clean, fun, descriptive alternative to masturbate. Can be performed on one's self, or to a partner. So you could flank your own mango (this sounds the best: "flankin' my mango"), or flank someone else's mango. Plus, it works for both women and men, because "mango" can be seen as either male or female parts.
I came home last night and found my roommate flanking his mango in the living room. Then my ladyfriend and I went upstairs, and I flanked her mango.