Longtime partner becomes adversarial

DEAR HARRIETTE: I find myself in some kind of an adversarial situation with my partner of 11 years almost every day. I say left, and he says right. I have an idea, and he shuts it down. It almost doesn’t matter what we are talking about; if I say something, he looks at me with disgust on his face and shoots down whatever words come out of my mouth without even considering what I have said. I hate this and find it intolerable. I have pointed out this behavior to him, and he brushes it off, saying I am too sensitive. I don’t believe that is true, but even if it is, so what? I am his partner.