(Cover) - EN Showbiz - Jennifer Lopez's kin are reportedly wary of her beau Casper Smart's true motives.

The 43-year-old superstar and her 25-year-old backup dancer lover have been dating since the breakdown of her marriage to Marc Anthony last year.

Jennifer appointed Casper as co-choreographer with Jamie King on her current concert tour with Enrique Iglesias. Casper is also spending quite a lot of time with Jennifer and Marc's four-year-old twin children Max and Emme.

Jennifer's loved ones are on guard.

"He's moved into her life and a little too easily, too," a source told People magazine. "I think her family is watching him closely."

Casper was captured in a photograph walking up stairs that lead to an exotic massage parlor in New York City around Jennifer's July 24 birthday.

Jennifer is said to be becoming curt with Casper.

"She's getting frustrated with him, short-tempered when she's around him," the source revealed.

Still, close friends don't believe that she'll end her relationship with Casper anytime soon.

"Jennifer is the kind of girl who doesn't like to be alone," the insider said. "Until she finds a replacement, I think, he's around." (C) Cover Media