John Legend lived a sweet sweet fantasy in Las Vegas.
Teigan also took to Instagram following the performance, expressing her jubilation: "Mariah pulled @johnlegend on stage at her Vegas show and as a lamb, 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!!"
Watch the full performance here:
And just because Carey is look especially on point these days, check out her latest few snaps following Saturday's serenade: