Everything about him, I love my to-be MIL too, but we lived with her for a period of time and I've gotten the chance to tell her I love her. Mostly during a break down of some sort, but on many occasions I've told her I love her. We've been spending more time with to-be FIL, this past weekend he invited us to a camp, we had A BLAST! On top of all the amazing things we did, we sat around fire, drank beer, and talked. To-be FIL is not really the type to open up and especially talk about his feelings but I saw a side of him I hadn't really seen. Even after FI fell asleep, his dad and I stayed up talking probably another hour. It was awesome, we get along really great. What I'm getting at though, the next day when we were parting ways, I wanted to tell him "I love you" but I don't know, I didn't do it. I'm curious when you started telling your in-laws that you loved them. I guess it will probably happen when we actually get married.