Cole Sprouse turned 26 on Saturday, August 4, and to mark the occasion, his Riverdale costar and rumored girlfriend Lili Reinhart took to Instagram to publicly wish her “love” a happy birthday.

“It seems as if the world would still be a stranger to me, if not for you. I’m so thankful that our paths intertwined to form this beautiful adventure,” Reinhart captioned a photo of Sprouse, which appears to have been taken during their trip to Mexico back in April. In a rare revealing message, she added, “Happy birthday, my love.”

Fellow Riverdale cast members commented on the post, with Madelaine Petsch writing, “F**K this is cute,” and Skeet Ulrich leaving two heart emojis.

Reinhart’s Instagram stories also offered a glimpse at how the two celebrated Sprouse’s big day, with a helicopter ride over a glacier and a picnic 7,000 feet above the ground.

The intensely private duo — who play fictional couple Betty Cooper and Jughead Jones — have been the subject of dating rumors since July 2017. However, both stars have been reluctant to talk about their romance, with Sprouse tellingPeople magazine in November, “Whether you dismiss those rumors or whether you encourage those rumors, it’s giving people who are, in my opinion, a bit entitled to your personal life more power.”

“The more you let people in on that, the more people feel entitled to it and the more it becomes problematic with whoever you end up being with in the future, so I take that very seriously,” he continued. “So I just never talk about it because it’s not anyone’s right to know. People can speculate all they want; people speculate about me with every member of the cast practically, but it’s really no one’s right to know.”

As for Reinhart, she admitted back in January that it’s “brutal” to date while in the spotlight. “People are just dying to know information about if I’m in a relationship or not. I understand the interest, but it’s called a private life for a reason. And it’s not something that I owe the world,” she told V Magazine.

“People are going to say anything and everything,” she added. “They’re going to say that I love KJ [Apa], they’re gonna say that I love Cami [Mendes], and they’re gonna say that I love Cole: It’s inevitable.”

What you do think about Lili Reinhart’s birthday note for Cole Sprouse? Let us know @BritandCo!

(photo via Jamie McCarthy/Getty Images)