R. Kelly Lawsuit I Made You a Star And You Pissed on Me

R. Kelly is an ungrateful tightwad who screwed over the guy who made him a star ... at least according to a new lawsuit.

Derrel McDavid says he's managed R. Kelly for decades and helped him navigate from a nobody to a superstar.

Things soured last year ... and Kelly and McDavid parted company.  According to the lawsuit they made a deal ... Kelly would give McDavid $1.3 million and they'd walk their separate ways.

McDavid says Kelly made the initial $300K payment, but the deal called for additional $40K a month payments for 18 months and he hasn't received a cent.

McDavid's suing for the $1M balance.

We reached out to Kelly ... but we haven't heard back.