Beyonce and Jay-Z partied with Cameron Diaz and her boyfriend, Alex Rodriguez on a recent night out.

According to People, Cameron and A-Rod arrived at his teammate CC Sabathia's birthday party seperately, clearly trying to avoid being spotted together.

A source told the mag: "It was obvious that they were deliberately avoiding each other.

"The two of them seemed hyper-aware that everybody was staring at them, waiting for them to interact."

Although she spent little time with her beau, when Jay-Z and wife Beyonce turned up at the 40/40 club, Cameron chatted with the superstar singer and the Yankee team's wives before busting some moves on the dance floor.

The source added that although Cam adnn A-Rod didn't interact much, they kept “within each other's eyesight the entire night.”

Why do you think Cameron and Alex are so keen to keep their romance under wraps? Tell us your theories on Twitter @areyouentwise.

We're still holding out hope for a Justin/Cameron reunion!