My mom and I had a pretty big falling out last year and we haven't spoken since. I don't want to go into too many details but I've always has a contentious relationship with my mom and a lot of it is about money. When I lived with my mom, I was the only one who consistently had a job and I had to pay for things for all of us. I still have trauma around it and I swore I wouldn't give my mom another dime ever again.

My brother asked me a few days ago if he could have $50 for groceries. I transferred him the money right away. I am getting paid in a few days and I called up my brother to ask him if he needed a bit more money for groceries. I didn't get an answer so I called his gf and she told me that he didn't buy groceries a few days ago. Now if my brother had just told me he needed $50 I would have given it to him but I didn't understand why he felt like lying to me about it.

He called me back after he got out of class and I asked him what he really did with the $50 I gave him. He told me not to get mad at him but he gave it to my mom because my mom had asked him for $50 and he doesn't have it. I got really pissed off with him and I told him he betrayed my trust by lying and going over my back to have me give my mom money when he knows about the problems we have. My brother got really upset with me and told me I needed to get over myself and this beef I am having with my mom and how tired he is of having to be the in-betweener for us.

Am I in the wrong here?