Camila Mendes fell in love with Charles Melton because of his "tenacity".

Camila Mendes

Camila Mendes

The 'Riverdale' star paid a gushing tribute to her boyfriend ahead of the release of his movie 'The Sun Is Also A Star', as she opened up about what made her fall in love with the actor.

She wrote on Instagram: "i remember the day @melton told me about this project. we were still just friends then. he hadn't even been cast yet. they hadn't even started casting. all he told me was "i'm going to play this role, i am daniel bae." aside from having the biggest heart out of anyone i know, his passion and tenacity are part of the reason i fell in love with him. watching him throw his entire heart and soul into this story of love taught me a lot about the kind of person he is.

"i'm probably sharing too much, but before we started dating he'd often get mad at me for trying to bring logic into love. he taught me that love doesn't have an explanation, it either exists or it doesn't. it was his vulnerability not only as an actor, but also as a man, that taught me that valuable message, one that is so relevant to this film. i'm so proud of you charles, and so grateful to have witnessed this beautiful journey of yours. can't wait for the world to see what you're capable of ... happy premiere day!! #thesunisalsoastar (sic)"

Camila was previously forced to reveal that Charles' Valentine's Day tattoo was a prank.

The 24-year-old actress posted a photo of her 28-year-old beau on her Instagram on the day, sporting an inking of "Cami" written on his pecs, but later revealed the truth behind the design.

Camila took to her Twitter and wrote: "The tat is fake lol thought it was obvious from the sticky patch around it but guess not. (sic)"