Selena Gomez Smooching The Weeknd in Paris

Selena Gomez staked her claim on The Weeknd with a serious this-is-MY-bf kiss on his cheek ... which we're sure had nothing to do with you-know-who being in town too.

Selena packed on the PDA Tuesday after his concert in Paris. But the "Starboy" singer was also performing at Wednesday night's H&M fashion show, where his ex, Bella Hadid, was doing her model thing.

Potentially messy? Sure. But Weeknd belted out "Nothing Without You" as Bella and Gigi Hadid strutted, and there was no drama apparent to the naked eye.

For the record, Selena was NOT at the H&M show.