Kanye West let Ray J know what he really thinks of him during a surprise performance on “Late Night With Jimmy Fallon.” Back in April, Ray J showed that he was not over ex-girlfriend Kim Kardashian, releasing a song about her titled, “I Hit It First.”

Kardashian was his "co-star" in the infamous sex tape leaked to the Internet in 2007. Kardashian catapulted to fame as a result of that, and since moved on to West, with whom she now has a daughter, North.

Though West did not comment on the song, he stopped by Fallon’s show Monday night to perform his song “Bound 2” which is off his new album “Yeezus,” and changed some of the lyrics. Dissing Ray J, who is singer Brandy’s little brother, the 36-year-old rapped, "Brandy's little sister lame, man, he know it now. When a real brother hold you down you supposed to drown."

On “I Hit It First,” Ray J apparently wanted to make sure people remember that he was with the reality TV star first.

In the music video, the leading lady looks exactly like Kardashian and in one scene even rolls around on a bed with Ray J during filming of a homemade video. Ray J sings, “I had her head going north and her a-- going south/But now baby chose to go West,” and he makes numerous references to Kardashian liking basketball players and athletes.

Ray J originally denied the song was about Kardashian, however, saying, "It's a song, it's not about that, it's about a concept," he said in a radio interview with New York radio station 97.1. "People going way too deep. They just gotta keep it on the surface [sic]. I'm not trying to create no war. It's all love; we're doing music.”

He later admitted that he was in fact talking about the curvy beauty.