I guess it depends who you are talking to
If she is out and doesn't mind I guess it is alright to call her husband. It will get confusing if you call her husband, SO, etc. Either you are confirming she is a he which you may not want to do in that setting, or you are making yourself look gay which may make the setting uncomfortable too. Nothing wrong with being gay, but it has it's own issues in a group setting. If they are not people you frequent, I would just call her your bff, or friend. If it is a social environment introducing your spouse also tells everyone you are taken. Your husband is suppose to be your best friend just as a wife is suppose to be a best friend to a guy. Kudo's for supporting your husband on these issues. You may want to ask him what he prefers.