I'm at a loss and really need advice.
My fiancé and I have decided to have our reception at a location that is limited on space. Due to this restriction, we have decided to only invite the children that are actually in the wedding party to the reception. (2 flower girls and 2 ring bearers are my nieces and nephews, junior bridesmaid (15 years old) is the groom's daughter and 2 guest book/welcome girls (15 and 11) are his nieces-his brother's/best man's daughters) we are offering babysitting for those children who would like to attend the ceremony and can't attend the reception. I've explained the size limit and our decision to have wedding party children only at the reception to all my friends that have kids and they've been more than understanding.
Now the issue-
The groom's brother and best man (I've known him for 12 years and have always viewed him as a brother)- continues to call and hassle me about inviting his fiance's daughter. He's called me 3 times putting pressure on me to make this exception. He says if i dont let her come then his fiance wont come to the wedding!! extremely selfish imo.
My fear is that by making this exception I will upset my other friends who have children that aren't able to come to the reception. Friends who I've known their children their whole lives and am close to them, whereas I've never even met his fiancé or her daughter. (Now an important side note to make here is: he's been married 2x before and this is his 4th engagement.. He has known her for less than a year and just got engaged to her.. So we feel like he loves being engaged and married and is quite chronic about it)
After saying no to him 3 times and explaining all the issues at hand, even saying my mother (who is paying for EVERYTHING) has said no, and offered babysitting at the hotel, etc.. He still is persistent. He has called his mother (who hasn't even offered to pay for the rehearsal dinner), and finally his brother-the groom.
The groom, instead of standing our ground, caved and said that he would talk to me and my mom about it! We then proceeded to argue because he'd changed his mind about the fiance's daughter so easily, when we've been sta ding our ground for 5 months! He said he understood his brothers point now which is that the girl feels like his daughter and its not fair to have his 2 actual daughters (who we have both known their entire lives) at the wedding and not his future step-daughter (whom we have never met). Also, the groom is sick and tired of dealing with the drama so he said screw it and let her come. The problem is that-my friends/family members who've been understanding about the kids not being invited will get upset and offended that an exception has been made and they still couldn't bring their kid.
My mom said I either cave under the pressure and explain to people that have a problem w it that I had no choice and was blackmailed or stand my ground still but that it may cause problems in my future family (my in laws). I don't have any idea what to do and I feel like my future sister in law is not trying to be welcomed into the family very well.. I feel like if I give up and let the girl come then I'm going to be very resentful and not forgive my brother in law or sister in law for their selfishness.