Justin Bieber may be back together with Selena Gomez - but it doesn't mean he only has eyes for his on-again, off-again love.

In a move that could upset the often jealous Gomez, the troubled singer, 20, got close to model Amber Rose, 30, at the ASCAP Rhythm & Soul Music Awards after-party sponsored by Bai5 antioxidant beverage in West Hollywood nightclub Bootsy Bellows on Thursday night, sources tell Breaking Celebrity News.

"Justin walked over to Amber's private table and they began chatting," an onlooker tells Breaking Celebrity News of the pair's party run-in. "They talked for more than 15 minutes- and even exchanged numbers. She was smiling and laughing."

At one point, the source continues, the two posed for pics, which both later posted on Instagram.

Though Rose is married to rapper Wiz Khalifa, Gomez has proven she isn't cool with other women contacting her man- As Breaking Celebrity News exclusively reported, the starlet flipped when she found texts from