Adele, 27, invited the couple to join her on stage after they got engaged during her song 'Make You Feel My Love", reported Female First.
"I thought there was a fight at first! I saw loads of camera phone lights go on and loads of arms go up and I thought it was a fight! Come up here - I know, I get stage fright too but come up," she said.
When the pair, whose names have not been revealed, got on stage, Adele probed them on their relationship and admitted the proposal was the "most beautiful thing" she had ever seen at one of her gigs.
"It's amazing to think you've been going out longer than I've been making music, and you've got a baby as well, called Alfie. That was the most beautiful thing I've ever witnessed at one of my shows," Adele added.