Devin Booker and Kendall Jenner might be exes, but somebody clearly forgot to tell their thumbs, because the flirting, trolling, and straight-up NSFW energy is VERY much alive and thriving! And yes, it all went down in public... because of course it did!! Related: Devin Booker Claps Back After Fans Accuse Him Of Wearing A Toupee! The whole mess kicked off thanks to Fanatics mogul Michael Rubin, who just posted a clip on Instagram from Kendall's appearance on Jimmy Fallon's late-night TV show.