50 Cent's Son Denies Dissing Him, But Says Dad's Music Sucks

50 Cent's son isn't shy about critiquing his father's music -- he says it SUCKS, but he also thinks everyone's getting the wrong idea about his own new track.

Marquise Jackson tells TMZ his song, "Different," isn't a shot at Fiddy ... even though the track includes the line, "Lost my pops, he's still alive."

Marquise has said his relationship with his dad hit the skids when he was about 10, and it hasn't been the same since. He says there's deeper meaning to his song than a shallow shot at "pops."