How much say so does my brother have?

My parents have a living trust. My brother is the only one of 7 children on it. (while there is not enough room to explain the circumstances, it was done underhanded) If my mom outlives my dad, it will be changed to what her and dad orginally agreeded to. My parents are 83 and 88 and as of now, owe nothing on their house. Last week, my dad and my brother applied for a home equatity loan for $60,000. My mom said she wasn''t signing and my brother told her THEY didn''t need her signature. How can they get a loan against the house when her name is on the deed too? What happens if my dad dies before my mom does? Is my brother responsible for the payments or will my mom have to make the payments to avoid a forclosure? My mom has a letter from her attorney saying that my brother has no say so with the house until BOTH of my parents are deceased. How can he have any financially say so? It seems like she going to have a financial burden on her that she didn''t ask for.