Justin Bieber kisses Selena Gomez
Justin Bieber kisses Selena Gomez Reuters

Selena Gomez had a few tearful moments at her 21st birthday party, when on/off boyfriend Justin Bieber made an appearance. According to People, the Come and Get It singer "started to cry" when she saw the 19-year-old Canadian pop icon.

Bieber was dressed casually, in a black-and-green jacket, which was perhaps a little out of costume. His former girlfriend was throwing a gypsy-themed party. And all of this was at the Revolve Beach House in Malibu, California.

"Justin arrived at the party in his leopard-print Audi R8," a source said, "He was casually dressed and carried a single rose."

"Justin and Selena went into the house to talk and were inside for a long time before sneaking out together," another insider added.

The two also enjoyed a few intimate moments, despite rumours of a break-up.

"She was all over him," a source told Hollywood Life, "They were definitely touchy-feely and shared some kisses and back rubbing."

The most interesting part of the evening though, was at 2am, when the couple got in a car and left together, according to The Sun.

Meanwhile, other celebrity guests at the bash included Julianne Hough, Nina Dobrev, Ashley Benson, Jaden Smith and Derek Hough.

Gomez broke up with Bieber in January but he set tongues wagging after posting an intimate photograph of himself with the former Disney star, sparking speculation of a possible reunion. The two were also spotted giving each other a kiss on the cheek while meeting up backstage at the Billboard Music Awards held at the MGM Grand Garden Arena on 19 May in Las Vegas.

Previously, in an interview with InStyle magazine, Gomez opened up about her relationship with Bieber and said the time spent with the Boyfriend singer was far from a fairytale romance.

"It's uncomfortable that everywhere I go, people know. I don't like that," she said, adding, "But Justin and I never really focused on the attention. You can't help who you date. So I wouldn't swear off that or say that's what I want again."