Jennifer Lopez back with one of her Exes?

Jennifer Lopez and Casper Smart are kicking off 2015… as an on-again couple!

Multiple sources tell ET that the former couple rung in the new year together in Las Vegas. 

The American Idol judge was in Sin City for her “The Best Is Yet To Come” New Year’s Eve concert special at Caesars Palace.

The 45-year-old singer dated her 27-year-old choreographer for about three years before calling it quits in June 2014.

While cheating allegations on Casper’s part were rumored to play a part in the break-up, the twosome kept it friendly post-split and were snapped together several times after parting ways. First, driving around Los Angeles together in August, and again in October when they were spotted having dinner at La Conversation in West Hollywood, Calif.

In 2013, Jennifer opened up to ET about how happy she was with her then beau, saying, “It’s a sweet relationship. It's kind, it's healthy… it's supportive.”

In November, the singer shared her views on love to ET again while promoting her book, True Love.

“A relationship should be supportive, uplift you, it should make you feel confident, feel better, they should be adding to the relationship that's already inside you,” she shared.

And while she’s still seemingly navigating the romance waters, Jennifer has a healthy perspective on how to make any relationship work.

“I know for sure that you have to love yourself first,” J.Lo added, “It's a key to life. If you don't love yourself, really nothing is going to go right.” ...ETNews