Entertainment Movies Jason Segel & Girlfriend Alexis Mixter Split After 8 Years Together: 'I Will Never Stop Loving You' Alexis Mixter announced her and Jason Segel's break-up in an Instagram post on Thursday By Alexia Fernández Published on April 29, 2021 08:05 PM Share Tweet Pin Email Photo: George Pimentel/WireImage Jason Segel and his longtime girlfriend Alexis Mixter have parted ways after eight years of dating. Mixter, a 42-year-old artist, announced their split in a heartfelt Instagram post on Thursday alongside a photo of the two. "This is a photo of two best friends. This guy and I have shared so much life together. Changed each other at a soul deep level. All for the better," Mixter wrote in her lengthy caption. "The depth of our bond was something I could never have anticipated." "I've never spent so much time with another person, grown so much alongside someone else, laughed so much, cried so much, shared so much," Mixter wrote. "It is odd to write about the end of a relationship, especially when the friendship that still exists is so full of life." Jason Segel: It Was an 'Honor' to Play David Foster Wallace in The End of the Tour She continued, "But change happens and we made the decision quite a while ago to let ourselves grow away from what our relationship had been and into what it was becoming." Mixter also reflected on "announcing a breakup on social media" which she said was "a strange feeling." "Some won't understand why it is necessary and that's okay," she wrote. "Having a public romantic relationship is not easy. Ending one feels like navigating a road that doesn't even exist. We are private people when it comes to our personal lives and I intend to keep it that way." Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories. "My feelings while writing this are only ones of love and gratitude. Gratitude to the universe for putting this man in my life the way it did and then allowing us the grace to decide that what we had, could become more. Because that is what our friendship feels like. More," Mixter continued. "More than either of us could have asked for in another person." "This post is a tribute to love and friendship and those relationships that make life worth living. Thank you J for being my best friend," she added. "The person who shares all my favorite jokes, sees who I really am and all I want to be, loves me unconditionally and makes me always strive to be bigger and better than I was yesterday. I will never stop cheering you on with every cell of my body. I will never stop loving you unconditionally. (This is an old picture but I chose it because we both love it and it was from such a great day.)" The This Is 40 actor and Mixter began dating in December 2013. They kept their relationship lowkey and made their red carpet debut in 2016 at a fundraiser hosted by Sean Penn. While the former couple did not speak about their relationship in public, Mixter did share a sweet birthday tribute to the actor in January 2020 alongside a photo she had taken of him. "I'm a day late because yesterday was spent celebrating you, the way it should be, unplugged and surrounded by friends and family," Mixter wrote in the caption at the time. "In your 40 years on this earth you've done so much and come so far," she continued. "I'm inspired by you every day and you've taught me that my heart is big enough to hold more love than I ever imagined." She added, "Thank you for being my best friend above all else. I'm so happy you were born. Here's to 40 more happy birthdays, I love you 🎉💕 (I had to pull out this photo from a while ago because it was such a great day and you look good with a cheese plate)." Segel has yet to publicly address the split.