Selena Gomez and Justin Bieber. (Adriana M. Barraza/WENN.com)

Justin Bieber appears to have proved his on/off relationship with Selena Gomez is on again for the holidays after they were photographed kissing during a romantic pre-Christmas ski trip.

The young pop couple was rumoured to have split last month  when reports emerged suggesting they had called off their relationship due to their hectic work schedules.

However, they have since been spotted together on several occasions, and they gave the clearest indication yet that the romance is back on when they were snapped smooching at an airport in Salt Lake City, Utah last week.

Bieber and Gomez reportedly enjoyed a festive skiing trip with another pop couple - Taylor Swift and Harry Styles, who were also spotted on the slopes of Salt Lake City.