Mallory Edens -- the daughter of Milwaukee Bucks owner Wes Edens -- is PISSED that DeMarcus Cousins just signed with the Golden State Warriors ... saying, "It's not cool to try to win a chip on your own anymore huh."
Boogie -- a four-time NBA all-star and two-time All-NBA selection -- signed an extremely team-friendly deal with the Dubs that gives the reigning world champs maybe the best starting five in league history.
This, of course, ticked off Mallory ... who wondered if the whole deal was someone playin' a trick on her.
"R u joking this is just nuts at this point," Edens posted on social media.
We feel your pain, Mallory ... but hey, Giannis and the Bucks ARE in the East -- so at least the inevitable Warriors beatdown wouldn't happen until next June ...