Jen Aniston & Renée Zellweger's Battle For Bradley Cooper!

The two evenings played out similarly for Bradley Cooper: hunky rising actor squires a blonde, 40-year-old A-list actress to an Italian dinner in NYC. The only casting change? He had a different leading lady on his arm each night!

After wining and dining Jennifer Aniston at the West Village's Il Cantinori on June 18, The Hangover star turned his attention not even two weeks later toward Renée Zellweger, with whom he shared an intimate meal at Upper East Side restaurant Antonucci on June 30.

"They were flirty," an eyewitness tells OK! of Bradley, 34, and Renée (who also just happened to bump into each other on June 25 in Paris, where they embraced in the street). "She played with her hair a lot and would often touch his arm. At one point he leaned in, like he had a secret to share. He spoke into her ear and they both giggled."

But what about Jen and Brad 2.0? According to a pal of Bradley, it's been strictly business since the two co-starred in He's Just Not That Into You. "He's friends with Jen -- and Renée."

A pal close to Jen, however, says she's ready to advance their offscreen relationship. "She's definitely into him. It's like a high school crush -- she says she gets butterflies when she's around him."

The only problem? So does Renée!

"Renée joked that she was a cougar," says the onlooker at dinner. "When the check arrived, they both reached for it. She told him she wanted to buy him dinner to pay him back for something, and when he opened the check, it already had her card in it." And while the duo left in separate cabs, Bradley was overheard telling Renée, "You should call me."

So where does this leave them all, besides in a love triangle? Pick up the new issue of OK!, on sale everywhere now, for the whole story!