Getting your next relationship set up before dumping your current S/O. Generally involves cheating (at least emotionally) on your current partner with the intended future partner. Refers to playing on the monkeybars, where you don't let go of the first bar until you've grabbed on the second.
Bill: "Well, your brother just sent the Save The Dates for his third marriage - they haven't even finalized the divorce yet!"
Joe: "Yeah, the monkey branching SOB did the same for his second marriage as well - all his relationships 'overlap,' if ya know what I mean."
OR
Joe: "Sue and I decided to try an open relationship."
Bill: "I dunno, sounds like she's monkey branching to her *next* relationship."
Inspired by the movie "Money Ball" - the establishment of a team or lineup in which the most attractive, kind, but also under-rated girls or women are merged in order to create a perfect squadron of bitches.
Guy 1: Dude I hate all our current bitches.
Guy 2: Goodness Gracious! Lets create our own Money-Bitching roster.
Guy 1: Thank the Lordus.