Tatum and Dewan, who share a 5-year-old daughter named Everly, released a joint statement confirming their separation in April.
“We have lovingly chosen to separate as a couple,” the statement said. “We fell deeply in love so many years ago and have had a magical journey together. Absolutely nothing has changed about how much we love one another, but love is a beautiful adventure that is taking us on different paths for now.
“There are no secrets nor salacious events at the root of our decision – just two best friends realizing it's time to take some space and help each other live the most joyous, fulfilled lives as possible.”
A representative for Jessie J did not respond when reached by People for comment on the reports.