Gomez, 20, is currently at the festival promoting her two films "Hotel Transylvania" and "Spring Breakers" and her Canadian boyfriend is on hand to help her out in his native country, reported E! online.
"Bieber was sitting in on Gomez's junket interview with her Hotel Transylvania costar Andy Samberg. The couple were then seen holding hands and Biebs was stroking his girlfriend's back as they went into the elevator," a source said. Bieber, 18, and Gomez have been dating each other for the past one year.
In pictures: Bend it like Mumbai yogini Natasha Noel
Photos: Varun, Taapsee, Jacqueline promote 'Judwaa 2' on 'Dance Plus 3'
Instagram's newest sensation: Check out these photos of Bruna Abdullah
Photos: This is how Chitrangda Singh looks without make-up
Photos: Malaika Arora parties wearing see-through lace dress