While Rihanna was at the Met Gala on Monday, Chris was celebrating his 20th birthday.

According to people.com, Brown recently had a small birthday celebration with friends and family in Virginia.

Asked how she was on the carpet outside the Met party, Rihanna smiled but did not answer.

Inside at the bash, after Kanye West finished his set, partygoers erupted in cheers when Rihanna – still clad in her power suit – joined the rapper onstage for a duet of his tune, “Say You Will.” She then sang her hit, “Live Your Life.”

Check out Rihanna at the Met Ball below: