AITA for leaving my bf bday dinner after his mom took my seat?

AITA for leaving my boyfriend’s birthday dinner after his mom took my seat “as a joke”?

I (25F) have been dating my boyfriend Matt (27M) for almost two years. His family is very close, and his mom in particular has always been a little… possessive? I’ve tried not to make a big deal out of it, but it’s clear she doesn’t like that I “take up his time,” and she’s made passive-aggressive comments like, “I hope I don’t lose my son to some girl,” even though we’ve been together for a while and I’ve made every effort to be kind and respectful to her.

Anyway, last weekend was Matt’s birthday. He invited me to dinner with his family at a nice restaurant. I dressed up, got him a gift I knew he’d love, and was honestly looking forward to the night.

When we arrived, I noticed his mom had saved the seat right next to him for herself. That’s fine, whatever — I sat on his other side.

But right before we ordered, his mom made a “joke” about how I always need to be next to Matt and said, “Let’s see how you handle a little separation!” Then she literally stood up, looked at me, and said, “Scooch, sweetie,” motioning for me to move down a seat so she could sit between us.

Everyone at the table laughed — Matt included.

I was so stunned I just quietly got up and moved. For about five minutes I sat there, feeling small and humiliated while she leaned over Matt like he was her date.

So I stood up, grabbed my bag, and said, “Actually, I think I’m gonna head out. Hope you have a great birthday, Matt.” And I left.

Matt blew up my phone later saying I completely overreacted, embarrassed him in front of his family, and “can’t take a joke.” His mom texted me a “sorry you were so sensitive” message, which just made it worse.

Now he’s not speaking to me until I apologize. I honestly feel like they were the rude ones — but it was his birthday dinner, so now I’m second-guessing everything.

AITA?