I'm, with Tish. Except for the part where if you flat-out asked a person if he was in a relationship, they'd necessarily tell you the truth. That's what we'd like, hope or even expect, but unfortunately, that's not always the case.
I met a guy once and we hit it off spectacularly. I flat-out asked him if he had a girlfriend, he said no and wore no ring, so I felt ok to proceed getting to know him better.
Being that I wouldn't think to lie to someone about my own relationship status, little did I know that 'technicalities' will always mess things up and liars use them to their convenience. He told the truth in that he did not have a girlfriend. However, he did have a WIFE and since I didn't specifically ask that question, as he put it, he "didn't lie to me, he just didn't tell me the whole truth." He didn't wear a ring because as an aircraft mechanic, he could easily lose a finger by wearing one.
Yeah, that ended INSTANTLY.
So, instead of asking him about a wife, you may want to ask like Tish siad about the relationship or dating or seeing someone, or however broad you want to put it, because **IF** he is being deceitful to one woman by going behind her back and playing pattycake with you, then believe me sister, it's even easier to lie to you.
One more time on the wedding ring issue: My father has never and will never wear a wedding ring in the 40+ years my parents have been married. Happily, I might add, thank goodness :) I was taught that marriage isn't worn on the hand, but in the heart.
Best of luck to you,