Justin Timberlake became a wedding singer on Saturday Night at the nuptials of Jessica Biel's college friend and her new wife.

Following the SCOTUS decision that legalizes same-sex marriage in all states last Friday, the singer's wife's Tufts University roommate, Dana Panzar married Amy Wicker in Norwalk, Connecticut.

US Weekly reports that while the wedding couple was celebrating and dancing with the guests, the "Love Never Felt So Good" singer who danced with his actress-wife enjoyed the band so much that he went on stage, sat on the keyboard and serenaded the newlyweds with "Señorita."

"Throughout the night, Justin really let loose and he started dancing in the middle of the wedding circle having an amazing time dancing to this great band. Then Justin decided he wanted to put on a little concert for the two brides and he jumped on the stage," an eyewitness told US.

"Imma start something, and all the fellahs gonna look at the ladies, who just got married tonight. And all the ladies gonna look at the ladies, you know what I'm saying," Justin started.

The eyewitness added "It was awesome and so special for the brides and all the guests who were so impressed!"

The bride's friend, Jessica also had a great time dancing at the party. "She looked amazing. You would never know she just had a baby because she is slim and trim."

Biel, 33, and Timberlake, 34, just welcomed their son, Silas in April. An insider told US previously that "The A-Team" actress has always seen herself as a mother of boys, so things are going really well for the couple. The source added, "Justin is so excited, he doesn't know what to do with himself!"

On Father's Day, the "Social Media" actor posted a photo of him carrying their 2-month-old baby on Instagram. "#HappyFathersDay to ALL of the Dads out there from the newest member of the Daddy Fraternity," he wrote.