And while she was doing so her current beau, Alex Rodriguez, watched in the wings.
Lopez and Diddy (Sean Combs) dated from 1999 until 2001 and on Saturday night they had a reunion that turned heads.
They shared a warm hug during her final All I Have show at Planet Hollywood.
Diddy, 48, watched her racy performance before joining her on stage for their reunion.
And J.Lo, 49, seemed delighted to see her former lover again in Sin City
A source revealed: "Jennifer saw Diddy in the crowd and sang to him. She seemed to be performing with a wink and a nod to him.
"At one point, she shouted out Diddy's name so the entire audience knew he was there.
"Then she screamed out Alex's name too. So she was very aware her ex and current boyfriend were both in the audience.
"She also performed a tribute to her kids Emme and Max."
RadarOnline.com reported recently how Lopez and Rodriguez almost bumped into another of her former boyfriend's Casper Smart recently.
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