Fame Flynet 1 / 28

Jennifer Lopez isn't the only one getting pampered by Casper Smart.

The backup dancer-turned-choreographer makes it a point to spoil her 4-year-old twins (with ex Marc Anthony), and stopped by a recent Xbox 360 event in L.A. to score some games for Max and Emme.

"He was going on about how he loves playing with them," says a witness.

PHOTOS: Jennifer and Marc, the way they were

Smart, 25, is equally enamored of his girl, 43.

"He's madly in love with her," the insider says of Smart, who will join Lopez on the European leg of her tour in October.

Adds the source, "It's not just that she's his lover, she's also his best friend."

Smart and Lopez first stepped out together in Fall 2011, just a few months after her painful July split from Anthony, whom she wed in 2004.

VIDEO: Half-naked Jennifer Lopez shows off her boxing skills

During her Sept. 14 appearance on Katie Couric's talk show, Lopez opened up about the much-discussed 18-year age difference between her and her new man.

"Until somebody brings it up, I don't think we really think about it," the singer revealed. "We're just two people who have similar interests and love a lot of the same things and who get along."

This article originally appeared on Usmagazine.com: How Casper Smart Plays Dad to Jennifer Lopez's Twins


Celeb House Swap

Bikini-Clad Jennifer Lopez Flaunts Tight Abs, Swims With Casper Smart

Shortest Celeb Marriages