Watch: Chrissy Teigen loves it when John Legend goes onstage with Mariah

Maybe the idea of Mariah Carey serenading your S.O. onstage would be a Heartbreaker. Well, not for Chrissy Teigen.

The Lip Sync Battle co-host gave us the mother of all reactions (as she often does) when Carey sang Touch My Body to a blindfolded John Legend in Las Vegas this weekend.

An eager Legend hopped into Carey's prop bed, and a member of her team secured a blindfold to the All of Me artist.

"Don't be mad," Carey told him while wearing a sparkling red dress with two hip-high slits. Then she caressed his neck with a giant pink feather.

And how did Teigen feel about this moment between her husband and Carey who apparently "go back like babies and pacifiers?" She relished every single moment of this One Sweet Day.

In a video posted to her Instagram, Luna's mom enthusiastically cheered along with the audience and showed off some sweet moves. In her caption, Teigen confessed to knowing the lyrics to the entire Carey catalog and thanked the singer for an "amazing night."

Guess it's true what they say — sometimes "a hero comes along."