Even supermodels have relationship problems. Who would have thought? The latest victim of love is Alessandra Ambrosio. According to In Touch Weekly, Alessandra Ambrosio and her baby daddy fiance Jamie Mazur are on a "trial separation."

"They've been living apart. They're still on friendly terms because of the kids and spend time together, but for now, they are separated and there will be no wedding."

On Tuesday night, the Victoria's Secret supermodel and Jamie both attended the Day by Day fashion show in LA -- but didn't exactly act like a loving couple.

"They arrived and left separately," an eyewitness tells Life & Style. "She showed up smiling with two friends and hung out in the VIP area about 30 minutes before the show started. Jamie arrived with a pal just before it began. They sat together to watch the show, but as soon as it ended, Jamie and his friend left while Alessandra hung around to talk to her friends. She then went to the afterparty at Wax Rabbit -- Jamie was nowhere in sight."