Megatron recently joined the Lost Light, sure, it was hard to trust him even though he changed his side, Autobot, but once the war was over, Megatron didn't know what else to fight for. He knew you were a Decepticon, it was a big burden to see you in the Lost Light and know he is your former Leader, but he managed to keep his emotions in check well.

Rodimus, the new Prime, captain of the Lost Light, knowing the tension between you two, decided to play with fire, making you two sleep in the same room for a while, also because there were no other rooms for Megatron.

You were late returning from a mission, tired and exhausted you headed to your room, opening the door... You could see Megatron sitting on his bed...

"You're late, how did it go out there?" He asked, he seemed like he was waiting for you for a while now.