Are Salma Hayek and former fiancé Francois-Henri Pinault back together - or just friendly exes?

By Sara Hammel
September 08, 2008 02:00 PM

The couple announced the end of their 16-month engagement in July, but the two stuck close together–and were all smiles–as they attended a birthday party on Saturday.

“She stayed by his side almost the whole time,” a party guest told PEOPLE of Hayek, 42, who also brought along Valentina Paloma, her 11-month-old daughter with Pinault, to the celebration for Stevie Wonder’s 7-year-old son Kailand Morris. “It was so cute–Francois-Henri was carrying the baby, smiling, and playing with her. He obviously adores Valentina.”

Pinault was spotted relaxing on a yacht with a woman in Italy late last month, but the French billionaire, 46, looked comfortable and happy to be back by Hayek’s side as the two noshed on sushi and fruit salad in the sunshine.

The party had a tennis and Olympics theme and was thrown at a country club in Pacific Palisades, Calif., by Kailand’s mom and Stevie Wonder’s wife, Kai Milla Morris, who even sprang for a very special birthday surprise: The Jonas Brothers made a brief appearance to serenade him with “Happy Birthday.”

All three Beckham boys–Brooklyn, 9, Romeo, 6 and Cruz, 3–enjoyed the party sans their famous parents, with Brooklyn spending hours on the tennis court hitting balls while Cruz put on another break-dancing show during a kids’ dance-off.