Mary Lambert, the featured vocalist on Macklemore & Ryan Lewis' gay marriage anthem Same Love, says Sunday's Grammys weddings left her in tears.

(Related: Madonna, Queen Latifah join Macklemore at Grammy's Same Love Weddings.)

Lambert, who is openly gay, discussed the performance with Billboard on the red carpet.

“[It's] really beautiful,” Lambert said. “I have literally been crying non-stop. Truly. It's a really emotional experience to be a part of this. Not just being a first time Grammy nominee, but the fact that the song means so much to so many people and to be sort of at the epicenter of that. And here the hook that I wrote, like, in two hours in a little vocal booth … I can't even. I don't even have words.”

Lambert added that song's phenomenal success was “stupid cool.” (The video is embedded on this page. Visit our video library for more videos.)

(Related: Conservatives go nuts over gay-inclusive Grammys weddings.)