Wtf do I do? Am I valid for feeling like this?

My dad hasn’t been in my life since I was 15 and when my brother was a baby. my dad fought custody of my brother when he was 3 and he did supervised visits temporarily until my dad’s sister emotionally abused my brother and he lost custody. since then he’s denied being me and my brother’s father and we haven’t seen him since. Fast forward a couple years later, i’m currently college student at a university not far from home, during the fall semester, i found out my dad was a professor teaching at my university but i didn’t let it bother me. when we walk by each other in the halls we avoid eye contact and don’t speak. i told my mom about him being a professor there and she told me she might pop up with my little brother there to “get his reaction”. I thought she was joking, until today. Today, my brother calls me to tell me he and my mom are coming to campus. I didn’t think nothing of it, but when they got here she walks us to my dad’s building. When we get there, my mom starts walking down the hall in the ear where his office was and a couple classrooms and found him teaching a class. she instructs my 12 year old brother to sit in the back of the class, and when my dad saw this he had a mixture of co fusion and shock on his face but had to continue to teach his class. my mom walks away and tells me to walk away and leave my brother in the class. As we sit, i asked her why she did that and she said “your father needs to see his son. see how he’s grown and looks like him” i told her she was wrong and how long she wanted him to be there, and she said she wants him to sit the whole time there. i will never forget how uncomfortable my brother was because u can tell he didn’t want to be there either. after class, we went to get my brother and my dad went off on my mom and told her not to bring her son to his place of work like this and that he wouldn’t do that to her if it was the other way around. he didn’t even call my brother his son. this has mentally affected me.
Wtf do I do? Am I valid for feeling like this?
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