The 35-year-old reality star and 32-year-old DJ both attended Lopez's 47th birthday party in Las Vegas amid their respective dramas with singer Taylor Swift.
Kardashian and husband Kanye West are feuding with Swift over West's song "Famous," which includes the controversial lyric "I made that [expletive] famous." Kardashian released a secretly recorded conversation between West and the singer last week after claiming Swift approved the line.
The Keeping Up with the Kardashians star added fuel to the fire prior to Lopez's party by sharing a Snapchat video of herself singing "Famous." The clip sees Kardashian and her friends sing along to the controversial lyric.
Harris, meanwhile, split from Swift in June after 15 months of dating. The couple's breakup turned ugly after Swift was quickly linked to actor Tom Hiddleston and revealed she had written Harris and Rihanna's hit song "This is What You Came For."
"Hurtful to me at this point that her and her team would go so far out of their way to try and make me look bad," the DJ tweeted after Swift's rep confirmed the singer's role this month. He was later spotted wearing sneakers from West's Yeezy line.