Aaron Rodgers -- HITS THE CLUBS ... Still a Sore Loser

Green Bay Packers quarterback Aaron Rodgers hit up the Hollywood club scene last night ... rollin' into Bootsy Bellows on the Sunset Strip ... but it's clear, he's still bitter over the infamous 2012 jersey bet.

Let us refresh your memory -- right at the beginning of the '12 season, Rodgers made a friendly wager with one of the guys from Boyz II Men ... that if the Packers lost to the 49ers, he'd have to wear a SF jersey.

The Pack lost -- and Rodgers TOTALLY WEASELED OUT OF THE BET LIKE A CHUMP!!!!

Anyway, we called him out on the b*tch move for months ... and when we ran into him in L.A. last night, it was clear ... dude still holds a grudge.