Bright - I do understand how you feel, but just two points (not quite a 2 x 4) The first is, how does your son feel about it? and the second - if you look at 'pursuer' behaviour, this is typical - you are fighting his battle and feeling hurt on his behalf etc.
Your son is old enough to say to your husband that he is sorry he wasn't invited. And to express his feelings to the rest of the family if he feels it is appropriate. It isn't your battle, however hurt and disappointed you feel. Focus on your needs and respond to those. (I am still learning this one)
Families are strange things - some are opening and welcoming and others close ranks. Families that produce MLCers are probably not very functional ones. MLC doesn't come out of a clear blue sky however blindsided we were by it.
