Selena Gomez celebrates Justin Bieber's 24th birthday

March 2 (UPI) -- Selena Gomez celebrated Justin Bieber's 24th birthday following reports they're back together.

The 25-year-old singer and actress dedicated a sweet post on Instagram to the recording artist on his birthday Thursday.

Gomez shared a picture of herself laughing while pointing to an Instax photo stuck to her forehead. Fans speculated in the comments that the snapshot was of Bieber or of Bieber and Gomez kissing.

"March 1, 1994 someone I know that happens to be super cool was born. Boom," Gomez captioned the post, which had received over 7.2 million likes as of Friday morning.

E! News reported Bieber spent his birthday with family and friends, although Gomez was absent from the celebrations. Bieber enjoyed lunch at the London West Hollywood before heading to MB2 Raceway for go-kart racing.

"When they arrived at the race track, Justin was greeted by his mom who was waiting for him at the entrance. He was so happy to see his mom and gave her a big tight hug," a source said. "Everyone walked inside hugging with their arms around each other."

"Justin couldn't wait to hit the race track and let his adrenaline junkie side come out right away. He was very into it and was going faster than anyone," the insider added.

Gomez and Bieber reconnected in October after splitting in 2014 after several years of on-again, off-again dating. The couple were all smiles while attending Bieber's dad's wedding in Jamaica in February.

"They're not putting pressure on themselves," a source told People this week. "They have both been through a lot since the last time they dated so they're getting to know each other again."