Justin Bieber And Selena Gomez 2014: On-Again, Off-Again Couple Celebrates A Friend's Birthday Together

Justin Bieber and Selena Gomez are giving their relationship another shot.

Just days after Bieber posted and deleted a photo of himself and Gomez on Instagram, along with the caption, "Our love is unconditional," reports claim the pair are "full-on back together."

"Justin and Selena are definitely full-on back together at the moment," a source told Us Weekly on June 17. "They spent [Monday] riding together on a Can-Am Spyder on Sunset Blvd. … Justin drove while Selena sat on the back holding on to [him]. He was incredibly sweet with her and they looked super happy and in love."

On Wed., June 11, Bieber sparked rumors that he and Gomez were back on once again when he shared a photo of Gomez with her arm wrapped around his neck and her cheek against his head. Although the photo was deleted just moments later, screenshots of the photo quickly began to circulate the web. A short time later, Hollywood Life reported that the pair had been together in Canada to celebrate a family member's birthday.

Following their Can-Am ride on Monday, Bieber and Gomez were spotted together at the birthday party of Alfredo Flores. In a video posted by rapper Khalil, Gomez was seen in a white dress with Bieber at her side.

According to Us Weekly's source, Bieber and Gomez "looked like a couple" and were "all over each other" at the bash.

Still, the source isn't so sure of the reunion.

"It is always on-and-off," the source explained. "Same story, every other week, every year. Now they are together again, next week they won't be."