Hi! Sorry about your hubby's feelings hun! I've read this same question a few times this week from different adoptees. I have no idea the right answer, but I know that if it were me...I'd be a lil sick of the instant gratification scenario. It especially gets old when it's so repetitive in occurrence over a long period of time.
Has he talked to her? Like has he told her that she keeps saying she is going to tell them, but she never does? I wonder why she does this? I can't imagine any other reason than to provide him with instant gratification in her own mind. Which really I bet it doesn't feel very gratifying to hear her say this anymore b/c he knows that the odds of her actually telling them about him seem to not be real high...being that she hasn't as of yet. Although maybe she is just taking a very long time to do so. Maybe she actually does have every intention to do so. Who knows. 1998 was a long time ago, so this confuses me.
How old are his siblings? How old is you hubby? This is not a fun situation at all. I know how I am...I'd end up telling them myself after asking my bmom what the deal was. Maybe.
Sorry for the lack of advice. I'm pretty confident you both will get some really great advice soon though.
Hang in there & I think it's admirable that you are trying to gain insight for your husband's situation.