Not to mention that he described his relationship with his wife as polyamorous during the interview. I can't imagine a scenario where this would be even remotely appropriate to discuss.
I personally view that as a sexual proposition, it’s a way of saying “I’m available”.
I think if you can say you have a wife, which implicitly tells your sexual preference and explicitly tells your legal family situation, then it's okay to add that you also have girlfriends or boyfriends as well.
Completely disagree. Every person I know who identifies as poly has their own definition of what that actually means, and many of them do not include "love" in their definition.
I maintain that discussions of such nature have to clear a “need to know” bar at work. There’s a lot of discussions about my relationship I’d be perfectly willing to have with friends that I would not discuss at work.
Regardless, you absolutely should not be mentioning your relationship status in any way during an interview. Single, married, poly, whatever.
I do wear a wedding ring though.