Mariah Carey blindfolds John Legend on stage

Mariah Carey treated John Legend to a blindfolded serenade during her concert in Las Vegas on Saturday (18Jun16).

The Hero star is currently in the middle of her Mariah Carey #1 to Infinity residency at The Colosseum at Caesars Palace, and when she performed her hit Touch My Body, she invited the R&B star to join her on stage.

John happily jumped onto Mariah's prop bed and one of the male dancers blindfolded him from behind as the diva stood next to him. She then teased him by rubbing a large pink feather on the back of his neck, much to his amusement.

Mariah posted a video of his appearance on Instagram later that night, noting John was a "Good sport" during the performance.

She also shared a clip of John's supermodel wife Chrissy Teigen in the audience, as she screamed and cheered her husband on while Mariah serenaded her man.

New mom Chrissy shared the same video on her Instagram page, and gushed over the moment, writing, "Mariah pulled @johnlegend on stage at her Vegas show and as a lamb (fan), I have never been so happy. There is no Mariah song I don't know the words to and I may have cried but whatever I LOVE YOU @MARIAHCAREY thank you for this amazing night for me and my family!!"

John also posted a photo of himself and Chrissy meeting Mariah backstage, writing: "We go back like babies and pacifiers", a line from her hit track Fantasy.

The concert rang in early Father's Day celebrations for John, who is celebrating the holiday for the first time after Chrissy gave birth to their daughter Luna in April (16).

On Sunday (19Jun16), Chrissy posted a sweet photo of little Luna wearing a onesie with the phrase "Happy Father's Day Daddy" printed on the front.

She added the caption, "Happy Father’s Day to the most perfect man Luna and I could ever ask for. Since the day she was born, you’ve done every bottle with me, woken up with me to keep me company through every night. You don’t mind diapers, get all the best burps, and read her Goodnight Moon like poetry. It makes me so happy to see so much of you in her smile and eyes that completely glow when looking at you. She will never look at anyone - anyone - the way she looks at you."

Chrissy added a tribute to John's father as well, writing, "Happy Father’s Day to your father, Ron. John is the amazing father he is because of you and Phyllis. You created and raised a man we are all so lucky to love. We love you, Johnny, endlessly, forever and ever to the Luna and back. Happy Father’s Day from Luna and I, and thank you to game 7 (of the NBA Finals) for providing the real gift here and getting me out of having to plan and overthink the day phew."

Sports fan will be watching the deciding game between the Cleveland Cavaliers and Golden State Warriors on Sunday evening (19Jun16).