Jason Segel and Alexis Mixter have broken up after dating for eight years
The artist, 30, shared the news to her Instagram account on Thursday
She said that they had made the decision quite a while ago to be friends
The photo was a selfie of the two side by side as they touched heads
Segel was on How I Met Your Mother from 2005 until 2014 with co-stars Alyson Hannigan, Josh Radnor, Cobie Smulders and Neil Patrick Harris