Nick Jonas and Priyanka Chopra Jet Set to India for Her Friend's Party

Nick Jonas is halfway 'round the world playing arm candy for Priyanka Chopra ... to which we say -- GREAT gig if you can get it!

The couple was all done up -- Priyanka in red, Nick in blue -- for an engagement party Thursday in Mumbai. The shindig was for an Indian billionaire's son, who we're guessing is a friend of Priyanka ... not Nick. It's her home turf, after all.

The loooong distance romantic weekend makes it a lock ... these two are serious.

Dating rumors started at the 2017 Met Gala -- but lately Nick and Priyanka have been inseparable, jetting off for all sorts of events and not shying away from PDA.