It wouldn't bother me at all with my DH, but I don't know how I'd feel in your situation.
My DH used to travel for work frequently and he and his coworkers would occasionally go out to bars, casinos, or whatever. I never minded. I know DH has gone to a few karaoke places when he's traveled alone (yeah, the guy likes karaoke, lol), and that doesn't bother me either. But I have complete trust in my DH, and it also helps that DH doesn't drink at all...I know from working as a bartender in college that alcohol can make people do things they'd ordinarily never do. I'd be much less okay with DH going out to bars alone if he drank.
I guess it just depends on what works in your marriage. I would think that if it bothers you enough to feel jealous, it warrants a discussion. I wouldn't want to have to feel that way all the time, ya know?
Stacy
Wife to K
Mommy to A (5) and twins E & S (1.5)
The biggest mistake I made is the one that most of us make...I did not live in the moment enough. I wish I had not been in such a hurry to get on to the next thing: dinner, bath, book bed. I wish I had treasured the doing a little more and the getting it done a little less. - Anna Quindlen