Brown, who turns 20 Tuesday, is laying low on his special day, spending time with family in Virginia. According to a source, Brown recently had a small birthday celebration with friends and family, also in Virginia.
Last month, Brown plead not guilty to two felony counts – assault and making criminal threats – in the alleged Feb. 8 beating of Rihanna.
The on-again, off-again pair have spent time apart lately, but reunited briefly in L.A. last month before Rihanna headed to her native Barbados. Asked how she was on the carpet outside the Met party, the singer 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."
In March, just weeks after the alleged confrontation with Brown, Rihanna celebrated her 21st birthday with a night out on the town in Los Angeles.
Reporting by ELIZABETH LEONARD