Is it appropriate for a married woman of 13 years to go to happy hour with her co-workers who are mostly male and single?

Would you want your husband to go out to happy hour with mostly single women co workers? Once you answer that, you have your answer. Personally, I wouldn't go out with a bunch of single men without my hubby, but that's just me. It wouldn't worry me or my husband, but the fact that you have asked the question means it would worry you and/or your husband, you have your answer. It depends on how loyal and mature the man and wife are. My husband and I have total trust in each other. I use to work at an Oil Company and was the only gal in the office. All the men were married, so was I and on occasion they would ask me to go for a couple of drinks (we were just buddies and I knew a lot of the wives). I'd put my finger up to them, dial the phone, check with my husband and he had no problem! He has gone out with a couple of women on business and I don't get all bent out of shape because he's called me about it. We've been married 35 years and never had a problem.