Uggh, I know what you mean. It's an on going joke between DH and I that if I tell FIL something he'll totally disregard it, but if my Brothrr-in-law tells him the exact same thing he will listen (then turn around and tell me). It's infuriating. Also, he talks over me and turns every conversation around to talk about his own POV.

I've just noticed lately how invalidated I feel between him, and somesometimes DH, and just people in general.