Is my husband correct to act like he "got dumped" and so hurt

My brother got engaged in May. His wedding is not until may of 2019! At one time when he was thinking about the wedding party he mentioned having my husband in the party. Both my brother and his fiancé have either a big family or life long friends (since childhood). So once they looked at things my brother and fiancé decided to cut out the inlaws. (Now my husband will not give me a definite answer if my brother actually asked him- which I believe he did not). On Thanksgiving my brother said to me the news and I shared it on thanksgiving night to my husband. My husband got upset, angry and has been so offended since. I told him I understand that you are upset but I understand their point also. He is acting like such a baby. I can not win the only way I can win is turning against my brother and saying what he is doing is so wrong etc/-- do I do that to have my husband just get over his butt hurtness and think I'm "choosing his side" or do I stick to my ground? The ironic thing is that just recently he made the decision not to do our 10 yr /my 40th anniversary trip bc of money. I was looking forward to this trip for SEVEN. Years! I didn't throw a fit- I acted like an adult.