Gellar and Blair, who played Kathryn Merteuil and Cecile Caldwell in the 1999 movie "Cruel Intentions," attended Pink's show at The Forum in Inglewood, Calif.
Gellar shared a photo Saturday on Instagram of herself and Blair at the venue. The actresses both wore black outfits to the concert.
"About last night.... @selmablair was the best date ever to go see @pink #beautifultraumatour," Gellar captioned the picture.
Blair posted the same snapshot on her own account.
"We have big smiles cause we were together at @pink concert and loved every minute. It was the most incredible show I have ever been to and my heart is still blown open by what this incredible woman and performer does on that stage and in her life. We love you Pink!" she wrote.
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