Days after sources told the Daily Mail that “Yeezus” rapper Kanye West wants to collaborate with legendary Beatles singer Paul McCartney, the New York Post is reporting that the musicians are now secretly working on tracks together in a recording studio. These tracks, one of which sources claim is shockingly titled “Piss on Your Grave,” may “develop into an album.”

Rumors of a potential collaboration first began when McCartney revealed in a Twitter Q&A last October that Kanye’s last album was one of his most recent purchases. Later, when discussing his track “Appreciate,” McCartney revealed Kanye was one of his ideal collaborators, along with Jay-Z. West was seen backstage at McCartney’s show at Dodger Stadium last week in Los Angeles, and sources are saying that the duo then finally talked about working together in person.

“Kanye and Paul have known each other for a long time but have become more friendly recently,” a source told the Sun newspaper. “Kanye really respects music legends and is still putting the finishing touches to his new album. He has been tapping Macca up for a while about working together.”

West is certainly an unlikely match for the 72-year-old former Beatle, but McCartney has often been praised for exploring ideas that are outside of his comfort zone. While a representative for West declined to comment on the reported collaboration, he confirmed to the Huffington Post that West is in fact working on a song entitled “Piss On Your Grave.”