He plays a hopeless romantic in the upcoming filmThe Sun Is Also a Star, and in real life,Charles Meltonis just as lovey-dovey.

“Something romantic that I do is I write letters tomy girlfriend,” the actor, 28, tells PEOPLE in this week’s issue of hisRiverdalecostarCamila Mendes.

He didn’t always embrace love, though, but has learned to over time. “I’ve been told from my loved ones growing up to always guard your heart,” Melton says. “But why do you want to guard something you want to give? It’s choosing who you want to give that to.”

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Camila Mendes, Charles Melton

In the movie, Melton’s characterDaniel falls in lovewith a girl (Yara Shahidi) he spots in New York City’s Grand Central station and feels an immediate connection with.

“I believe in love at first sight,” the former college football player says. “It’s this hopeful curiosity of seeing someone and just being in awe and not being able to explain it, but there’s something that draws you to that person. There’s something you don’t know and it’s just a matter of you being vulnerable enough to explore that.”

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THE SUN IS ALSO A STAR

Daniel finds out that his crush doesn’t believe in love, so he gives her 24 hours to convince her otherwise. “It’s a very vulnerable thing to do — take out your heart, metaphorically speaking, and put it all on the table for 24 hours,” Melton, who will also appear inBad Boys for Life, says.

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Over the course of that day, Daniel must prepare for his interview with Dartmouth College, where his parents want him to study medicine. Daniel, however, would rather pursue poetry.

Meanwhile, Natasha (Shahidi) is fighting for her family to stay in New York City and not be deported back to Jamaica.

The time crunch doesn’t stop the two from connecting over karaoke, where Natasha starts to imagine a future with the boy she just met. Daniel captivates Natasha with Tommy Jane and the Shondells’ “Crimson and Clover,” but off screen, Melton usually opts for a karaoke song fit for royalty.

source: people.com