You want to watch out with that one. There was a couple in NY state in just your position, who declined to rent out their barn for a same-sex marriage. Lawsuit and potential financial ruin ensued.
Believe me, we’ve discussed this. We found a great way around it from someone else that does this. When someone contacts them, they require facebook communication, preceeded by friending them. They can then ask very simple questions that never even discuss their sexual preference, but the facebook page exposes everything.
They then schedule accordingly. This is an oversimplified explanation, but you get the gist.