It's out of season for baseball, but a great time for paddleboarding – which Alex Rodriguez and Cameron Diaz enjoyed this week while on vacation with his two kids in Los Cabos, Mexico.

Clearly, Diaz seems more intent on learning the sport, while Rodriguez just enjoys a little relaxation on the high seas.

The pair, who have made habit of vacationing in Mexico, have been soaking up the rays in Los Cabos all week long.

It wasn't anything like their recent rockin' date night on Broadway, but on Sunday night, Cameron Diaz and Alex Rodriguez squeezed in some more time together – or at least tried.

Arriving separately at his teammate CC Sabathia's 30th birthday bash at New York's 40/40 Club, the couple strategically steered clear of one other and any prying eyes. In fact, Diaz, 37, slipped in and out through the side door while the Yankees slugger, 34, used the front entrance.

"It was obvious that they were deliberately avoiding each other," a source tells our friends over @ PEOPLE. "The two of them seemed hyper-aware that everybody was staring at them, waiting for them to interact."

Without any private rooms at the venue, the couple resorted to keeping a distance but "were within each other's eyesight the entire night," adds the source.

And even without some alone time with her beau, Diaz seemed to be having fun. Later, when club owner Jay-Z joined the festivities with wife Beyoncé, the actress chatted with the singer and the Yankee wives, in addition to hitting the dance floor.

"She danced all night long," says the source. "She wasn't hiding."

While Cameron Diaz remains mum about her relationship with slugger Alex Rodriguez, the Knight and Day star does proclaim herself a New York Yankees fan nowadays, despite growing up with the Los Angeles Dodgers.

Diaz, appearing on the cover of the August Harper's Bazaar, plays it coy about her current love life, though she is upfront about dating bad boys – and how they're an ultimate strikeout.

"Who doesn't like the bad boy, until you grow up and realize bad boys are not the way to go?" she says. "I'm done with that."

Not that she was outing ex Justin Timberlake as a bad boy. In fact, Diaz says she and Timberlake – with whom she'll appear in the upcoming movie Bad Teacher – "have laughed together for years. He is the funniest guy; you've seen the stuff he does on SNL."

Diaz, 37, may appreciate Timberlake's sense of humor, but when it comes to all-around sexiness, who's her idol? Oscar winner Helen Mirren.

"That woman is drop-dead sexy," Diaz says of the 64-year-old beauty, who appears in the new, brothel-themed film Love Ranch. "She's not trying to turn back the hands of time, she is just taking care of herself.” And, "she's a nudist!"

Their relationship ended in 2007 after four years together, but now Justin Timberlake and Cameron Diaz are set to rekindle a romance onscreen.

In Bad Teacher, a comedy about romantic rivalry, their characters connect when Diaz, 37 – playing an opportunistic, profanity-spewing middle-school teacher – gets dumped and sets her sights on Timberlake, 29, the school's already spoken for model instructor, according to Variety.

Although they played voice parts in Shrek the Third (Timberlake as a royal nephew to Diaz's ogre queen Fiona), the former lovers have never before acted together in the flesh.

Set to start shooting in L.A. later this month, the film costars SNL alum Molly Shannon, Jason Segal, Lucy Punch and Modern Family's Eric Stonestreet