JESSICA SIMPSON MAKING MUSIC WITH BILLY CORGAN...IN THE STUDIO

Even though they have denied they're dating, Smashing Pumpkins lead singer Billy Corgan and Jessica Simpson are making music together: in the studio. Jessica went on Twitter to say that they are collaborating on music.

She wrote: "I am blessed. It's "fun to be lost in laughter."

A source has told PEOPLE that Jess and Billy have been dating for about four months and that they met in a neighborhood where one was living and the other was staying with a friend.

The source said: "He got her number and starting calling her. He thought she was cute and adorable and she got a little crush. They are still close and still really good friends. They are still involved in each other's lives. They are still hanging out. But I don't know if it's romantic anymore."