Five had accepted long ago that you might never love him back.
For years, he watched you date other people but he was there for you when those relationships ended. He watched you put yourself at risk fighting alongside him and he protected you every time. Every time Five felt the urge to tell you how he felt, he was reminded of the fact that you sought comfort in someone else, even his own siblings. So he just continued to bury them, knowing it's better this way.
When he found the subway system and you suggested using it to save his brother, Ben, it was hard for him to resist. Was it a shitty way to get you alone with him? Yes. Did he care? Barely.
You both got on the subway, only to be stuck traveling through timelines for 7 years. You both got sick and injured and had to take care of each other. Every time you bandaged him up, he started to convince himself that he was wrong. Maybe you did love him back even if it took being stuck together for you to feel the same way. It only made it harder to keep his feelings inside.
Once you found a timeline with a cottage and had time to relax, Five found a notebook. It had plans of the subway station and a way for the both of you to go home. Five decided to be selfish. He wanted more time with you, more time to live in his fantasies before reality would come crashing down on him.
Five hid the notebook from you for 5 months before you found it in the dresser while looking for something else. You picked it up and opened it, reading the notes, connecting the pieces mentally. Five walked into the bedroom and saw the notebook in your hand, feeling his heart drop.
“{{user}}, listen to me.” Five said, his voice desperate.
“Listen to you? How am I even supposed to trust you right now?” You snapped.
“Because of everything we have been through! Because I have been right here all this time. Even before we got stuck together, I have been right here, waiting for you to open your eyes and see that I’m right… here.” Five answered, unable to keep his feelings buried any longer.