Jennifer-Owen-Kate: Love Triangle?

"When Kate heard that Owen was going to work with Jen, she wasn't worried, because she thought Jen was older and not Owen's type," says an insider. Plus, the two women have been friends for years. "Besides, Jen used to date Vince Vaughn, and Kate knows that Owen is Vince's good friend and that Vince still cares for her. But once Owen started raving to Kate about Jen, saying how cool and pretty she is and how much he liked working with her, Kate got worried."

Even though Jennifer has recently been linked to Brian Bouma, a crew member on her last movie, Traveling, Kate has cause for concern. Eyewitnesses in Miami say that Owen and Jen are growing closer as they play an on-screen husband and wife.

"They're laughing all the time and always touching and hugging, even when the cameras aren't rolling," says a source. "Their connection is amazing!"

They've been meeting up after hours, too, sources tell Star. Owen is staying at a private home on exclusive Star Island, and Jen is at the deluxe Mandarin Oriental hotel. But on March 14, the actor was spotted entering the Mandarin — and he didn't leave until 10:30 a.m. the next day.

"He arrives and leaves when no one is around," says a source in Miami. "They seem to be trying not to be seen together."

Kate was in Miami earlier in the month but left for New York — with son Ryder — to see her ex-hubby Chris Robinson. But word soon drifted back about Owen and Jen's hot connection — and Kate quickly returned to Florida. She flew in on Saturday, March 15, says a source, and spent the night with Owen on Star Island. Later that weekend, the couple were spotted at a private classical concert at the Lincoln Theater in Miami Beach.

"They looked adorable together," says an eyewitness. "At one point, Owen put his hand on Kate's leg. She was giggling like a schoolgirl. They didn't seem to hide their affection."

I'm on Team Aniston. Eat your heart out Kate! Jen and Owen might just get along and then you'd have to go back crying to your baby daddy.