Law & Ethics: Should I be concerned and should I take any further action?

I'm not gay and I've never been in a situation like that, but I think you should a) find a new place to work and b) look into what actions you have available. If they are going to react that strangely to such a minor mention of homosexuality, there is a good chance things could get much worse. Say a boyfriend calls you or they see you texting someone, they could freak out and pull some weird ****. Sorry you work with such assholes.