Justin Bieber Celebrates 24th Birthday Go-Karting With Friends -- But Where Was Selena Gomez?

Justin Bieber didn't need to do it big this year.

A source tells ET that the Purpose singer's 24th birthday celebration was super "low-key," saying, "He's all about doing things with friends, he's really not into the party scene at all."

The source adds that Bieber "got together with his boys during the day. Lunch and Go-Karts."

Justin's mom, Pattie Mallette, joined her son for the get-together, and the two sweetly shared a big bear hug upon seeing each other.

And while Justin's girlfriend, Selena Gomez, wasn't with him during the day, the source adds that the two met up later.

"They're together every night," says the source, who could not confirm how Selena and Justin celebrated or what she gave him as a gift.

"She's super creative and incredibly thoughtful -- she'd get him something sentimental, not necessarily something crazy expensive," the source says, adding that they are planning a short trip soon, just the two of them.

"It's been a busy month. Selena had a lot of work commitments and then they went to Jamaica for Justin's dad's wedding, and before that, Selena was in New York, solo. They haven't been on a trip, just the two of them, in a while and were talking about doing that soon," the source adds.

Prior to hanging out, Selena did take the time to post a super sweet birthday wish for Justin on Instagram, writing, "March 1, 1994 someone I know that happens to be super cool was born. Boom."

Reporting by Darla Murray.

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