Did I overreact? Please give me your opinion!!

Kendra
My boyfriend and I have been dating for almost a year. He has two children from his previous relationship with his babymother... Now, that you know the details, Here's the story. Lol 
Over the weekend we got into an argument about a confrontation w/ my sister's husband a week ago that I brought back up. My sister's hubby said some mean things about my boyfriend for no reason and some of those things he said was about my boyfriend's babymother (like she looks ratchet was ugly lol I know... it was kinda childish of him lol but oh well, He's entitled to his opinion.)  
So, My boyfriend said, "When I see him again, I'm going to confront him about what he said about me & my BABYMOMMA!"  
In my head, I was like.. WTF?!"😮😮 Why would you take ANYTHING he says about her personally? SHE'S NOT YOUR WOMAN. I AM!  I took it as he was defending her which by his words, he damn sure was. Idc what he says. 
Then, he says.. "She didn't have anything to do with this and she's my kid's mother and even tho, She's a pain in the ass, I still have to take up for her. WTF?!? I was in complete shock! 😔😡 I wanted to cry but, not in front of him. THEN I said, " I don't think it's fair that you always put her over me b/c she's your kid's mother. She's moved on, got married and has two another kids from her husband!" DAMN, GET OVER IT!!! If she needs someone to take up for her, she has a husband. 
THEN he said, "Well, you have your BROTHERS!"  At this point.. I begun to sit quietly b/c that's not the same as my point. So... I told him.. "You wouldn't get that pissed if it was me" 
 He insisted, " Yes! Yes! I would, you don't know what I would do" I rolled my eyes like yeah whatever 🙄 
He was like... I love you! I still couldn't believe he trying to justify his actions. What he said broke my heart. I don't think he would never understand. It's not because I'm jealous. That's like me saying... I will still fight over my ex if he's with another girl.  
After we augured, He left out the room and I begin to cry but, he didn't know I was crying b/c he left. I think I had every right to feel hurt, Did I overreact? OR Yes! I had a reason to feel some type of way about that?