My brother has a fake girlfriend

I live in a small town with my husband near the rest of my extended family. My brother lives 300 miles away. My brother has had a lot of problems with romantic relationships, he's been married several times and nothing works for him. The rest of my siblings are married or STB married. 1 1/2 years ago my brother met "Beth" supposedly on a dating site. Beth lives in our small town. My brother introduced Beth to us as his girlfriend. However, the only time he ever sees Beth is when he comes to our town for a visit and picks Beth up to come to one of our family's events, like holidays and weddings. My brother never touches Beth or even talks to her, yet insists he and her are an item. This year he may have seen her 4 times so far. I normally wouldn't care, but Beth is very nosy and asks lots of questions. The family is in the process of placing our mother in a care facility because she is very sick. We will be discussing the details of this at all the upcoming holidays and I'm not comfortable having Beth present during these talks because she really isn't my brother's girlfriend and I don't want her being the mouth of the south for our family. My other brother says to stay out of it, my mother doesn't want us to cause any trouble. My two sisters and I don't want Beth at Thanksgiving and Christmas. FWIW, Beth and my brother attended a family wedding in July and Beth brought a baby that wasn't hers to an evening wedding where children weren't invited. My brother has thin skin and a temper. Is it even possible to broach this subject with him and tell him not to bring his fake girlfriend to at least one of our upcoming holiday meals?

This might just be something you are going to have to grit your teeth and bare. Your brother sounds very stubborn and i think the more you push the more he is going to go against you. There is definitely no talking to him, but what about Beth? Is she as stubborn as him?