The reality star celebrated the pop icon's birthday by attending her show in Vegas. Lopez, now 47, rang in her birthday with friends and boyfriend Casper Smart following her performance. And another guest in attendance? None other than Calvin Harris, who joined in to party and lip sync some Kanye West after the Internet-crashing feud between Kim, Kanye and Harris's ex-girlfriend Taylor Swift.
The DJ posted a video earlier this week of himself lip-syncing Kanye's controversial Famous song. Kim also posted a Snapchat singing along to the now-infamous lyric, "I feel like me and Taylor might still have sex. Why? I made that bitch famous. I made that bitch famous."
And on Saturday night, the DJ posted a Snapchat video of himself dancing with the birthday girl. He didn't ignore Kardashian West either – a source tells WHO that the pair were friendly and chatted at the party.
"About last night...Pre birthday turn up!! @balmain," the singer posted on her Instagram on Sunday.
Kardashian West has been turning up in Vegas all weekend long, starting with an appearance at Hakkasan nightclub at the MGM Grand hotel on Friday. She danced and sang with friends, including Larsa Pippen, Carla DiBello LaLa Anthony and Maria Menounos. The same crew was there for Lopez's birthday, and Anthony posted an Instagram of the women with the caption, "Happy Birthday @jlo we had so much fun tonight!!! Concert was AMAZING!!"
The friends danced and sang along to all of JLo's hits, including Love Don't Cost A Thing, and several videos posted to Kardashian West's Snapchat showed all of the fun – and many selfies – of the girls' night out.
The fun continued with everyone singing "Happy Birthday" to Lopez with a giant cake. At one point, Lopez was struggling to blow out her candles and said, "It's a big one." Kardashian West then rushed over and says, "We'll hold it for you," but Lopez managed to blow them out before saying, "I got it, I got it."
Lopez's Vegas show, Jennifer Lopez: ALL I HAVE is her first-ever headlining residency at Planet Hollywood Resort and Casino. Performances continue through the summer.