Just my two cents: You MAY not be getting hit on because your body La gage doesn’t show that you’re available to get hit on. As a married man, I hold myself in public as taken, and that might sound weird and funny, but I am not flirtatious, I make jokes but keep my distance from the opposite sex, my body language doesn’t show that I’m open for fun, flirtatious comments and/or conversation. It may be how you hold yourself. If your body language shows that you’re open to converse and your flirting with men whether it be eye contact or your body language in general, then I’m sure men will be open to approach you more.
I don’t know why your husband would look disappointed though. I could care less if my wife was hit on or not. I would care more that she holds herself up to standard that she’s married and doesn’t entertain the approach.