Close family wedding etiquette - or - what is the right thing to do?...

by Anonymous
(Florida, USA)

One of my husband's nieces is getting married. This is a young woman who has always professed to love us dearly. Through the years, my husband and I have been very loving and supportive to both her and her sister and both of her divorced parents. Yesterday my husband received a call from his brother who, in a very matter of fact way, let him know that the two of us were invited to the wedding but our teenage (19years old) son who lives with us, was not. According to my brother-in-law, our niece has decided no teenagers in order to keep the head count at a certain number. My husband is very upset and although I am trying very hard to play the diplomat for the sake of the family, I am also very upset by this. I know it's her wedding. She should do what makes her happy. We have no right to ask that our son be invited. However, I come from a family where exclusion of a family member from a special event would never even be an issue. So, although, I want our niece to be happy and do what she wants for her wedding, I am feeling very disheartened with this matter. This has been a very unexpected thing and I find myself searching for the right thing to say or do. Any feedback would be greatly appreciated.
Sincerely,
Caring aunt but also (and first), devoted wife and mother