I have always done this. I don’t know why, and I certainly don’t like to - because it is perceived by most as inappropriate -, but I cannot help it.

So if someone can tell me how to not do it (spoiler: you can’t), I will be in your debt.

I don’t have a problem with this when someone is sharing bad news with me; It only happens when I’m being confronted or accused of something.

Now, if I’m in a full rage then there will be zero smiles from me.