Richardson and Dier have dated for years, but according to Richardson's interview in Cosmopolitan, she didn't have a big proposal planned.
"I didn’t prepare at all," Richardson told the outlet. "I had no idea when I woke up that morning that I was going to ask someone to marry me that day. I was totally in the moment and this gut feeling came up and coerced me to ask him to marry me and I did."
The whole thing was so chill, it happened at a food court — but that doesn't mean the moment wasn't any less special.
"We were at this outdoor strip mall eating pizza when it happened. When we were crying and having this really amazing moment that I’ll never forget, crying and holding each other and saying oh my gosh, we’re going to get married, we’re going to be together forever, we were like, we’re gonna have to do something about it because we didn’t have any rings. So we went over to this bush and got these twigs and each knelt down one at a time and tied these twigs around our ring fingers. We have them saved in a little baggie."
Those twigs actually inspired Richardson's real ring — at least, the one made out of something a little sturdier than wood.
"My engagement ring now, it’s custom made, it’s a really simple ring but it’s engraved like a twig," the actress told Cosmopolitan.
While the Split star has no issue talking about her relationship, it's her Instagram that really gives you a feel for this adorable, goofy couple.
Here's Dier secretly filming Richardson happy crying:
Here's them celebrating the city they met in:
And here's Dier bothering Richardson. (But not really because she loves it.)
Five Feet Apart hits theaters March 13. Dier and Richardson's love story is currently available on Instagram.