By Breaking Celebrity News Staff

Mark Ballas and Pia Toscano have officially called it quits after several months of dating; the news comes on the heels of Star magazine’s exclusive report that Ballas has been hooking up with Kristen Cavallari, his new partner on Dancing with the Stars.

The pro ballroom dancer and the American Idol finalist had been making beautiful music together since hooking up last April.

Ballas, 25, and Toscano, 22,  decided  to go their separate ways after a heart-to-heart talk this week about their demanding careers, according to PEOPLE.

"They both decided with everything going on that they couldn't give each other what would be fair," a source told the magazine. "They mutually decided this."

Ballas is currently paired up with reality TV star Kristin Cavallari for the new season of Dancing with the Stars, which premieres Monday on ABC  --  and Star magazine reports in its new issue that the two are already hooking up.

Toscano has been busying  touring the country with the American Idol concert tour and