I have a huge problem with this as well. I tend to think that my husband's relaxed, regular expression is an angry, irritated one. This sounds ridiculous, but we have gotten into some big arguments over this! I'll keep asking him what's wrong, and he says nothing, but from what I see on his face, he looks mad. One time during a pretty big argument I told him that it's his facial expression that set the whole argument off, and he exclaims " you're basing this whole argument on my facial expression? You know that you're really bad at reading facial expressions!" Then we both started laughing, and I apologized, because I know he's right!