Tatum posted an image on Friday night of himself posing as the "Bang Bang" singer kisses his chin. They're both wearing unicorn ears and horns.
It is the first picture of Jessie J on the "Magic Mike" actor's Instagram since her birthday in March. The couple had briefly called it quits late last year from their relationship that started in 2018.
"We've needed time to get to know each other," she said. "We've just had our first holiday together, which was wonderful, but that's all I'm saying."
CNN's Lisa Respers France contributed to this report.