These days, people are increasingly comfortable expressing gender in less traditional terms in order to better reflect their own identity. When you refuse to use someone’s preferred pronouns (he/him/his, she/her/hers, they/them/theirs, etc.), you’re refusing to acknowledge who they are. It may seem like it’s not a big deal, but using the wrong pronouns for someone can be extremely invalidating and hurtful. Always do your best to call people what they want to be called.