The guy could have an open relationship with his wife.

Even if he does OP didn't know that, which isn't fair.

Also, why would someone offer up information that you could blackmail them with? Especially on a first date

Yep, the correct response to this is to say "They sound great, when can I meet them?"

You'd actually be surprised at how many men will tell you about their wife/SO on a first date—especially those you meet through Internet dating. It's usually followed by "I'm going to break up with her as soon as her birthday's over/she's done grieving for a dead relative/she finishes school, etc...." (or something similar). I'm not sure if women do the same thing to men, but this has happened to me and several friends. Or it's possible he got half way through the date and decided he didn't like OP and thought the best way to let her down was to invent a wife and kids. Either way, he sounds like a jackass.

Polyamory and open relationships are becoming more acceptable too. He could be available without being single.

As others have said, he may not think of this as a date but a casual outing between friends. Or he may be in an open relationship. We'd really need a follow up to know for sure. But what I want to know is, why can't OP associate with married men? I associate with more than one married woman and it's never cost me any drama. As long as no one is immature or possessive, there is no reason to cut off all contact.

I'm married. I've seen no point to divorce as it's expensive and unnecessary at this point since I've found no one else to marry yet. At some point, I will need to make that decision. In the meantime, I desire and enjoy the company of women- not just for sex, but for the dichotomy women bring to my life. Should women run from me just because I've committed to taking care of my responsibilities while searching for a woman I can be happy with?

I should make it clear we've been separated for a long while.

^ Just get divorced, dude.

Easy for you to say. It's expensive and neither of us care to go through with it now. I'm not stopping her from dating. We get along way better now than ever.. so what business is it of yours. Point is, I'm honest with every woman I go out with about my current situation so that they don't have any surprises.

When you post your life details on the Internet it becomes everyone's business.

You know people like 19 who are married but have been separated for years, some over a decade are out there. Some even live in different states. They just feel no need to get a divorce. They keep the spouse and kids on their insurance and taxes. They live that way until one of them wants to remarry.

^exactly. I see no need to get a divorce. She's on my insurance. I take very good care of her and our kids. We get along. We don't need the dirt and stress of divorce. But since I do date, I feel it's best to be up front about my situation. I guess according to FMLers I should walk away from all that.

If it is an open relationship then at least you can say he brought it up on their first date and not a couple of months into things.