AITA for not wanting to invite my fiancés brother to my wedding
So me (F 30) and my fiancé (M 35) are getting married in october. Part of the wedding will be out of the country and it will be just us 2 and 3 friends that will also be best men and bridesmaids. After we return we'll have a private small intimate wedding in a small church in a forest that means a lot to me and my fiancé. We decided that we will be only inviting mine and his parents and the 3 friends that will be with us out of the country. Today we told his parents our plans and my mother in law is not happy that the wedding will not be traditional and that we won't be inviting more of the family members. She insists that we at least invite his brother and consequently his baby mama and his 3 children. The problem is i don't like them. Their children are wild and where they go is like a zoo, no manners and they don't listen a thing and are spoiled. Also my fiancé has a bad relationship with his brother and agrees with me. But i must state that the brother and his +4 will be invited with the rest of the family to a party after the wedding that will be the same day in a different location. I would also like to invite my maternal grandmother and grandfather to a church wedding but if i do then i need to invite also my paternal grandparents with whom because of my fathers death i am in a bad-ish relationship. They will also all be invited to the after-party. When the mother in law said to invite the brother my fiancé was quiet and then i said if that is a must then no children should be present. She said that who will look after them ( 5, 3 and 1 years old) and i said that they also have another pair of grandparents to take care of them. My mother in law is not happy and father in law said that its our decision and that it's just their suggestion, but if children are not invited then it has no meaning to invite just the brother and baby mama. Point of us getting married out of the country and in a small ceremony in church at home is that i dont want a lot of people around because i lost my dad young and these situations like weddings when a father walks a daughter down the aisle or graduation make me sad because i start missing him and I become a mess. I wish to have my ceremony with just the people closest to me that i care for and and not some that I despise because of his principal and family history. Am i the asshole?
Edit: As it seems it's not comon to have 2 weddings around the world. So let me clarify.
So the first wedding that will be out of the country, will be just a civil marriage at the registry office with us2 and other 3 friends and a dinner. This civil ceremony is what my country requires as prof of marriage certificate. We will be there 10 day. And we all wanted to travel to that country for about 3 years and decided to also when we are there get married. So its a trip and a civil marriage. The friends love this idea and see no problems with this.
The second one that will be at home in a special forest, is a church wedding with a priest and we choose to have it in a small chapel. So it's a religious wedding and not recognised by the state as ligal or official.
The wedding after part is just a little gathering for the family to celebrate because there won't be a big traditional wedding.
In my country we always get married twice, usually the same day so a civil ceremony and later a christian church ceremony.
Also my fiancé DOESN'T WANT TO INVITE HIS BROTHER. He was just caught off guard by my mother in law and did say nor yes or not the her idea. But today he told them that it will be as planned just 4 parents, 3 bestmen/bridesmaids and a priest.
The children were only hypotheticaly excluded from a chapel wedding and still invited to the after-party.