Selena Gomez & One Direction's Niall Horan hang in London [PHOTOS]: Barbara Palvin's 'boyfriend' smiles with Justin Bieber's ex and fans after Valentine's Day

Selena Gomez is pretty good pals with the boys of One Direction. So when the "Come & Get It" beauty bumped into Niall Horan in London on Sunday (Feb. 16), of course the two singers were more than happy to snap a few pics with fans.

Some Twitter fans posted these snapshots over the weekend:

‏@ellienovack: "Was so nice to meet @selenagomez and @NiallOfficial."

Of course the photos instantly went viral.

Gomez and Horan are NOT romantically involved. Rumors suggest that the 1D crooner is still dating stunning model Barbara Palvin. But did the alleged couple break things off right before Valentine's Day?

According to a Hollywood Life source, things actually got pretty steamy between the two pop stars - "Sel & him made out a bit [but] it wasn't a big deal... Would she see [Niall] again? Yes. He's being a gentleman and that is great for her. The last thing she needs is anything serious, but he's cute and he likes her."

Really?

Maybe hanging out with Justin Bieber's adorable ex was a breath of fresh air for Horan...

Do Mstars readers think Gomez and Horan would actually make a cute couple?