Instagram user @eatprayphoto spotted the interaction and posted some videos, captioning one "When you're having a drink at an empty hotel bar and @justinbieber appears out of nowhere and begins to sing on the piano" and writing "@justinbieber singing my girl to@selenagomez....is this real? Pure magic (sic)" alongside another.
She also posted a picture, taken by Selena, 23, of her and some friends with Justin and revealed the bad boy singer couldn't have been nicer.
Alongside the picture of a smiling Justin, 21, she wrote: "Photo cred: @selenagomez. He asked to sit at our table to chat, so impressed by the kindness (and realness!) of this guy tonight. Now a #belieber (sic)."
Justin and Selena last split up in October 2014 after almost four years of on/off dating but he recently admitted he will always love the singer.
He said: "[She] is someone I love dearly. I'm never going to stop loving her. I'm never going to stop checking in on her. I don't think if you end a relationship, you should end that, unless it was super toxic and you guys were hurting each other physically or mentally. We always respected each other and we still respect each other."
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