There is something which no one, including Riza, knows about me.
If you tell anyone this then I will burn you into such a crisp that they won't even be able to recognise you with your dental records.
I, Brigadier General Roy Mustang, the infamous Flame Alchemist, ladies man, have always wanted to have a family.
Which, when you think about it, doesn't really fit in with my persona. I mean what kind of ladies man with a suave smile wants children! They don't help with picking up women, not that I've tried that, of course.
So, when Riza and myself started dating, I was hopeful for us having a family. After all, a long-term committed relationship, surely that implies that you can have children. At least that was what I was going to use to defend our right to a child if Riza was to get pregnant. However, I wasn't going to tell Riza of my secret wanting of a family because I had always thought that she had never wanted children. Even though I saw her be very motherly with Edward, Alphonse and Winry I was never actually able to connect the dots to the possibility of her actually wanting to have children.
Maybe I should discuss this with Riza, but, the fact remains if you tell anyone this, then I will burn you into an unrecognisable crisp.