My Gamemaster is gender fluid

I have moved to a new city for my studies and searched for a new pen and paper group. Pen and paper is a table top role playing game, that I’ve played since I was a child and I didn’t want to drop this hobby because of me moving away.

So I’ve searched all groups in my new city and months later found a nice group. We’re 3 players and a Gamemaster, who I thought was a girl.

Turns out the person is “fae” basically everything but male, even though his sex is male. The person dresses like a girl and calls itself with female pronouns (but also is fine being referred to as it).

Now my Gamemaster seems to be a nice person, but I don’t know whether it is right or not. I feel uncomfortable because I’m afraid of doing something wrong in regards to religion or misgendering said person.

Is it a sin to call a person by the pronouns they wish to be called with? Is it bad to spend time with this type of people?

I really don’t want to be homophobic or anything else, but I’m really confused as I’ve never been in such a spot before. I don’t want to lose this group, it was really hard to find it…