Sexism

This has never before happened to me and I am pretty taken aback.
Today I was told that actions that are now second nature to me are sexist. I strive in all situations to be a gentleman at all times even if I am, shall we say, not particularly fond of the female in question. I'm not saying I'm perfect, I get short and snappy. Hey, I'm still human. But I am kinda shocked and, well, apalled that things that have become automatic reactions, e.g. holding doors open, the custom of ladies first etc, have caused my to be called sexist. It's ridiculous! It's simple manners. How can it be sexist? It's not putting women down? It's not placing them on a level lower than that of men. It's not debasing them. If anything, it's putting them ahead of men, ahead of myself anyway.
Call me sexist. I do not care. I will never stop being a gentleman.