The couple got engaged at the first stop of Christina's comeback tour (Fadil Tony/youtube)

Christina Aguilera has marked the first concert of her new tour by inviting a gay couple on stage to get engaged.

The singer, who has released two empowering singles — “Accelerate” and “Fall In Line” — from her first album in six years, Liberation, had a treat for her fans in Florida.

After performing the last song of her new album — a wedding song called “Unless It’s With You,” which includes the lyrics: “I don’t want to get married / Unless it’s with you” — she helped gay couple Ben Lear and Mike Kontomanolis to get engaged.

The star told the crowd: “I have a really special surprise that’s happening tonight. I want to welcome two special people to the stage, Ben Lear and Mikey K.”

After they were brought up, she asked Lear: “So, what’s happening here tonight?”

He answered by taking the microphone, turning to his already tearful partner and telling him: “I could not have imagined you could have a better moment than [with] this woman, who has inspired you throughout your whole life and has brought you through so many things.”

Facing Christina, he said: “Thank you for being an inspiration to not only everybody here, but to him. Thank you.”

Turning back to Kontomanolis, he gripped his arm and said: “You’re kind, you’re beautiful, you’re loving.

“Six years ago, you proposed to me and you gave me the opportunity to say yes. Tonight, in front of Christina, I’m going to ask you the same question.”

Lear took the ring out of his pocket, handed the mic to Christina, and got down on one knee.

Kontomanolis, crying too much to speak, repeatedly nodded in answer to Lear’s question, and the pair embraced and kissed.

Then it was time for Kontomanolis to speak directly to Christina, telling her: “You are so important to me. You’ve gotten me through so many important things.

“I don’t know where I would be if I didn’t have you and your music to lift me up and just carry me through.”

The pop star, who revealed earlier this year that her 2002 song “Infatuation” was about an ex-boyfriend who came out as gay, then thanked the newly engaged couple.

She said: “I wanted to share and dedicate this special moment to two people who have been tried and true through my life and supported me.

“I want to wish you guys the best of luck. Thank you so much. Congratulations, you guys!”