50 Cent and Estranged Son Roast Each Other on Marquise’s 26th Bday

50 Cent is crushing his son Marquise Jackson‘s hopes at a reconciliation … and what makes his latest diss even more cold-blooded is the fact it comes on his son’s 26th birthday!!!

The legendary rapper responded to Marquise’s on-camera olive branch Thursday with a very personalized dig buried in a promo for his ongoing European tour.

In the clip, we find Fiddy in da tub of his exquisite hotel, flipping through TV channels … only to see Marquise’s infamous interview where he claimed the $6,700-a-month child support wasn’t enough for him while growing up.

50 reacted with the facts … Marquise was once the beneficiary of $25k monthly support before the courts lowered it. The video ends with G-Unit members Tony Yayo and Uncle Murda teasing 50 … begging him for their own $6,700 payments.

Marquise saw the post as a glass-half-full situation, claiming his father has never given him a birthday shoutout until today … and even though it came with a diss, he reveled in the moment.

The birthday boy let a few jokes fly of his own — ribbing both Yayo and Murda for essentially being 50’s “yes men.”

He also returned fire at 50 Cent’s previous “Power” diss by posting a different scene — this one shows Michael Rainey Jr.‘s character murder his dad, Ghost. Remember, 50 had posted the scene where his character kills his son. So, no warm family ties going here!!!

TMZ Hip Hop recently spoke to Marquise … who says he’s willing to put up any amount of money to make good with his dad after all these years.