There is NO REASON for a married man to be hanging at the bar, the beach, or "hanging out" at the hotel. Period, end of sentence. NONE.
My husband has to travel sometimes with work, and occasionally he will have A (meaning one) drink after the meeting or whatever, but it is A drink and in work attire (shirt and tie). "Scantily clad" is not work attire, not appropriate for an office and therefore she's probably off hours and out for attention and to party. That's not what we're about, and I wouldn't want him partying off hours with women if I wasn't invited to go too. They do go to restaurants, but it's usually a nice restaurant with dress code and something he can enjoy that we don't get to go to with the kids. He's won awards where we go to nice places (most recent was Naples, Fla where his work paid for us to get freebies like designer fragrances, sunglasses, spa days, golf, kayaking, airboating, a sunset cruise, very nice banquets, dancing, a great party the last night). The difference with all that is that it is for you to bring a date (ME). And though there were idiots that got drunk and jumped on stage with the band, or danced on speakers, they were just that. I didn't say anything about them, but was like "wow....we need a few more drinks to catch up" and my husband was like "No way---these idiots forget that even though it's a party, it's still work and the president of the company is over there. She's fine with having fun, but she'll remember who can be trusted and how decisions are handled by things like this". We danced, had a nice time, but then snuck out of the party for a few extra drinks and hit the beach to be alone...
All that said for this: your husband needs to recognize that taking a work trip is not taking a college roadtrip with no responsibilities or real life. It's still real life. He's still married with kids. Secondly, bosses are seeing what's going on, and managers don't count. Real bosses: would they be pleased and feel he is trustworthy to make important snap decisions, based on how he's acting on this trip? Third: are these coworkers, or friends? You don't party and play with coworkers like that. Coworkers are for work. Friends are people you'd bring to the family and let us all join in together. Would he feel uncomfortable with that girl wearing that outfit and going to the bar, to meet up with his wife and children?
I can't tell you what to do because it's not me......not my situation. But I will say this: I don't care---if I didn't feel my husband could be trusted to handle himself correctly, if he blurred the lines between friends and work, if he couldn't remember to handle himself professionally on a business trip and play hard with us on our vacations, then he would NOT be going on the business trips. Business should be for business, and play should be for vacations. They are separate.
That said, there are 2 guys from his work that we consider friends, where they come to our house for BBQ or pool parties, we go to their houses for pizza and fight night, birthday parties, etc. But those 2 men were really the only guys my husband thought were worth being friends with outside of work: good family men who had similar interests but also family values and wives that would kick their butts just like me. (ha).