The "Boyfriend" singer dropped in as a surprise guest during Streisand's concert performance at the United Center in Chicago Tuesday night, where they performed the famous duet "No More Tears (Enough Is Enough)," with Grande admirably taking on the part originated by Donna Summer.
Streisand took to social media to share a snapshot of herself and Grande standing side by side in the green room before the show, which the songstress captioned, "Secret’s out. Thank you @arianagrande."
Grande commented on the beaming photo, "I’m sobbing ? love you so much. i cant. get over this. it’s just.... the most special and cherished experience ever. thank you."
The team-up came one day after Streisand teased the possibility of a collaboration by sharing a semi-cryptic snapshot to Instagram that was just a close-up of her well-manicured hands next to Grande's hand -- including signature finger tattoos and sweater sleeve.