It's hard for me to say this is meeting Io's emotional needs, but it's the closest either of them know how to do that. Also, on some level nothing could make up for what Io's been through, so I guess like, good for them? At least you extracted some short term benefit.
Real world morality aside (this is not the way to handle important discussions in a relationship), Misa has shown herself to be constantly thinking of Io's well being for quite a while. It makes their dynamic enjoyable to read about and it seems like there won't be much they can't handle as a team if they get through this. We don't know what messed up stuff Io's mom will do, but we may be past drama within the relationship itself.