Bieber took part in the 30th annual "Christmas in Washington" concert, where he met the First Family and probably made at least one server's night.

Hollywoodlife reports the couple, who stayed in the $10,000 a night presidential suite at the Four Seasons hotel, shared a romantic dinner at DC restaurant, Bourbon Steak.

An eyewitness told the website, "Justin and Selena were extremely polite and friendly. They were wearing matching red scarves and were very affectionate with each other. I don't think they ever stopped smiling."

In case you were wondering what the teenage popstar power couple enjoyed that evening, the insider says they split the organic chicken and filet mignon, and also enjoyed the wood roasted 'magical' mushrooms, black truffle mac and cheese and roasted baby eggplant. For dessert, they had coconut cream pavlova and crunchy profiteroles -- bringing the bill to around $120 before taxes.

That's quite the meal and we know someone else who never stopped smiling -- their server. The source tells Hollywoodlife, "Justin was very generous with his tip. Let's just say the tip was almost as the same amount as the entire dinner."

It's nice hear Justin is spreading the wealth around, but we aren't too surprised -- it is the holidays after all -- and just a few weeks ago the couple left a 200% tip to an IHOP server.