Abused

Trust is a hard thing to earn, an easy thing to lose, and an even harder thing to get back. Mal learns this the hard way.

First they earn each others trust even while Mals job is threatening there life.

Then Mals trust falters when he learns she hasn't told him everything but, in the long run ends up losing her trust despite fixing her.

Gaining it back. While that's a whole other story on its own.

The only question now is if he can gain what hes lost and manage to keep them alive.