"You get stuck up alone with yourself long enough and eventually you don't just become lonely, you change." He's breathing heavily, hands running through his hair as he shakes his head dejectedly.

"I changed. I don't think I can be the person you need me to be anymore." His voice cracks.

"I can't be the Mark you used to know. I need to find myself again." It's not you it's me. Mark needed more, Mars erupted something inside of him, he needs adventure, he doesn’t want to waste his life stuck… and he doesn’t think he can do that with you. “Thank you for waiting for me…but it’s time to move on.” He aims for a sheepish smile.