Mills, 30, announced the news Thursday with a lengthy caption on Instagram.
“I’ve had to accept there’s no possible way to capture a love of this scale or its significance to me, in a few paragraphs. That said, I’ll try, because so many of you supported us over the years like a family would,” he began. “So here it goes.”
“Our relationship has been in the public eye for the last 3 years. What’s ironic about my most public relationship is that behind the scenes it was the most non-superficial & grounding experience in my life. While it pains me our journey has come to a close, I mean it when I say I’m so incredibly grateful to have shared the last 3 years with someone as compassionate, smart & wonderful as Madelaine. The personal growth made possible by our time together I wouldn’t trade for anything.”
“Red carpets, parties, photoshoots, TV etc create this alternate reality where we are one-dimensional people, free of real world challenges, kicking our feet up, waiting for the next big job. I wish our lives really looked like a google image search of our names,” he continued. “In reality we’re ambitious & hard-working individuals, dealing with rejection, in different states/countries, wondering what the next best move is, trying to see friends/family, take care of our dogs, answering an ocean of e-mails, balancing REAL LIFE & doing it all while being separated by it.”
Mills went on to acknowledge the “mountain of challenges” the couple faced, noting that they helped him “do some very necessary growing up.”
“I’ve learned so much about myself & life from that unconditional love and support,” he said. “While I’m holding back tears I’m excited to see what you do next. I’ll always have your back.”
He added that he would not be deleting any of their pictures together, explaining, “I regret nothing.”
Mills and Petsch, 25, had been together since early 2017. Fans began speculating about a split earlier this month when Petsch attended Vanity Fair‘s Oscars afterparty without Mills, and when neither posted about the other on Valentine’s Day.
They were together as recently as December, when Mills posted a photo of the couple at Disneyland, writing, “I don’t always wear ears at @disneyland, but when I do it’s because @madelame made me.”
Petsch has previously been open about the relationship, speaking fondly of Mills in interviews and regularly sharing photos of the two on Instagram.
“I think my generation is extremely cynical about love,” she told Glamour in 2018. “I’m a huge advocate of showing my relationship online because love does exist, and I think it’s so important for our generation to know that love will win. No matter who you love, what you love, it will win.”
The actress said that before she met Mills, she was “fully single and didn’t talk to anybody.”
“And then I met him and was like, ‘Oh my God, this is what they say,'” she said. “It sounds patronizing when they say, ‘When you know, you know,’ but [now] I know.”
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Petsch also shared the story of how she first met Mills, an actor/musician, in an interview with Cosmopolitan in 2017. As it turns out, they connected on Facebook after Mills reached out to congratulate Petsch, who plays Cheryl Blossom, on season 1 of Riverdale. (He had auditioned for the role of Jughead, which went to Cole Sprouse.)
“I think we just randomly had mutual friends, so we added each other,” she recalled. “We kept in touch very rarely, not even that much, from January to February, and then the day I got back from season one in February I was bored in L.A., believe it or not. I was like, ‘What am I gonna do?’ I got my hair cut and he texted me like, ‘Let’s go to a movie!'”
“We hung out and spent every single day together that I’ve been in L.A. since then,” she added.