"She told me one day, 'Dad, Ariana Grande is a great singer','You're not a great singer'," he recalled.
Surprisingly enough, Legend said that it was his version of "Beauty and the Beast," which he sings with Grande, is what turned his daughter into an Arianator. He continued "Eventually she became such a big fan of Ariana that she's, like, unfavourably comparing me to Ariana Grande."
He did admit that Luna doesn't completely dislike her Grammy-winning dad's music.
"But in addition to listening to Ariana all the time, she listens to my Christmas album," Legend added.
Switching gears, Lilly praised "The Voice" judge on the real persona he portrays in the media, something that John credited his wife with helping him discover.
"I think being married to Chrissy actually encourages that because she's so real with her fans all the time," he told the late night host.
"If you were paying attention on Twitter the other night, she did just a random Qiamp;A just because she felt like doing it."