The proof comes in the form of photo booth snapshots taken at an engagement party for another singer who is lucky enough to count the A-list singers as friends.
E! News is reporting that the party - which was held in Nashville over the weekend and doubled as an ugly sweater party - was a nice chance for the music stars to let their hair down and have a good time.
"They were extremely friendly to everyone at the party and fit in just great," says one of E!'s sources. "They acted normally and were very down-to-earth, regular people. Both of them together were the life of the party. They didn't show too much PDA, but you can tell they were a couple and very into each other."
"Blake and Gwen were great. They looked happy," adds another source. "They were having a great time and dressed in spirit. Blake gave a nice little toast to Raelynn and congratulated his close friend…what a friend would do for another friend."
But don't let the seeming lack of affection fool you. It seems that, in private at least, the couple are working to take their romance to the next level.
"Gwen and Blake are steaming up," claims a third source close to E! online. "They have been having some great times with each other the past few months and are on the same page of life now. Blake is extremely supportive of Gwen and her kids' transition. Blake is really great with kids and loves being around children. He has a lot of patience."
In spite of that, it seems Gwen and Blake won't be spending the entirety of the holidays together. Gwen is planning on splitting her time between the new boyfriend and the father of her children, Gavin Rossdale.