Hollywood relationships aren't exactly known for being long-lasting, but Mary Mouser and her actor boyfriend Brett Pierce certainly seem to be breaking that mold. The two met at the party of a mutual friend back in 2015, and haven't left each other's side since.

In fact, they recently celebrated five years of being together.

You might recognize Brett from his role as Young Eddie in A Million Little Things, or as Cuff from Stuck in the Middle. The good-looking heartthrob has also appeared in a season 14 episode of Grey's Anatomy. 

"On November 11, 2015, I found myself talking to this cute, hot, badass chick at a party," Brett wrote in an Instagram post he dedicated to his girlfriend on Valentine's Day of 2018. "Little did I know, she already had a test to see if I was into her. Dates later, she told me that she crossed her arms during our first convo and if I like her/was paying attention, I would likely mimic her body language. Wanna guess if I crossed my arms?"

The two have been going steady ever since and even recently celebrated a half-decade together. Right before Christmas, Mary posted her own moving tribute to Brett on social media. 

"Five years with you has felt like five minutes," she wrote. "Happy anniversary to the most spectacular boyfriend — who I am so grateful to say is also my best friend, my whole heart, and the only one I would want to be locked in a cabin with for the whole weekend."

"I love how funny, silly, caring, thoughtful, intelligent, kind, and brave you are," she lovingly continued. "Thank you for so many amazing adventures, and for being all I ever need."

Aside from posting about their upcoming Hollywood projects, both Brett and Mary seem to absolutely be each other's biggest fans. "Check out @missmarymmmouser kicking a--," Brett gushed ahead of the Cobra Kai premiere. 

We're obsessed with how in love these two are.