AITA for calling my wife's best friend a jerk and walking out of the dinner she arranged?

I was a foster kid - there were some rough times but I had one good foster home that I stayed with for most of my teenage years. It's where I met the couple who I consider to be my parents now. I've had a few other helping hands along the way too. I was fortunate, and most people's results may vary.<br><br>I don't talk a lot about being a foster kid. It's not something that defines me, and it was a lifetime ago. I'm married, I have two kids, a great job, and a nice home. That's what I care about.<br><br>So it really caught me off guard when Wendy, my wife's best friend since childhood, went into a long explanation of how impressed she was with whatever it is she thinks she knows about my childhood, and how admirable it is that I was able to beat the odds. My son clutching at my pant leg was what really brought it home for me. Up to that point I was just embarrassed. But when I looked at my son, I got really angry.<br><br>I said, "Wendy, you're a jerk. Or something's wrong with you. Maybe both. I'm going to go take care of my kid and get some fresh air."<br><br>Over the protestations of my wife, I took my son out of the restaurant and we went home. My wife followed about two hours later, very quiet.<br><br>When we turned in for the night, she said, "You're an asshole."<br><br>I said, "Why?"<br><br>She said, "You embarrassed Wendy. I know you don't like her, but she really looks up to you and she was just trying to compliment you."<br><br>I said, "You know I don't like her because she's an asshole. And I'll think about apologizing when she learns to mind her own business."<br><br>My wife said, "She didn't mean anything by it."<br><br>I said, "Then accept my apology."<br><br>She said, "No! You need to apologize to *her*."<br><br>I said, "What if I don't?"<br><br>She said, "Then maybe I shouldn't talk to you for a while. I need some time to myself. Go sleep in the guest room."<br><br>I did. Now it's the next morning and I'm thinking maybe I really overreacted. Maybe something is wrong with me, and I'm just looking for a fight.<br><br>AITA?