Lizzo Raps About Sydney Sweeney's Jeans in New Music

Lizzo is riding Sydney Sweeney's jeans as a way to sell some new music ... rapping about the controversial American Eagle ad campaign in an upcoming track.

Check out this snippet of a new Lizzo song she just teased on social media ... Lizzo raps, "Fat ass, pretty face with the titties / B*tch I got good genes like I'm Sydney."

It's unclear when the song will drop, but it looks like Lizzo already filmed a music video. She doesn't give the track a title either ... but the Sydney lyric has folks buzzing.

Lizzo's already trolled Sydney for the controversial ad ... getting political after people started claiming the commercial was a racist dog whistle.

Now, Lizzo's using all the attention Sydney's getting to her own benefit ... so she can line the pockets of her own jeans.