Fucking ungrateful ass?

I got up and made my SO food while he was still sleeping. We don't eat the same this was just for him. And it was a great morning but he wasn't hungry so he just put it away for now. And then we got in a pointless argument. I wasn't even fighting we just disagreed to something and he got mad that I wasn't on his side basically. And you know what he did? Put the food in the garbage. And sits at the table with me and says I just threw that food away. I was so in shock like what the fuck?!?!? Who does that? I had no words. I'm still in shock. What an asshole right?!?!? He's 12 in a 20 yr body obviously. He's never did this before. I kind of just want to cry. Like how fucking ungrateful. And we live together to make it better. Why start acting like this now? I'm not crazy right? This is so rude and uncalled for right?

Guys when I say we just simply disagreed on something that's all it was. He said a person was a certain way and I said they weren't. Which by the way this person is MY family. I just want some feedback and support. Theres noone I can really vent to personally so it's frustrating.

Update: I took a showet after this happened and he came in and said "hey sorry I was a jerk and tossed away the food. It was rude." And then he walked away. He kinda said it like he knew he was wrong but didn't want to apologize. I reallllllly want to make steak for dinner (which I don't eat) and feed it to my dog lol. I know it's wrong and I should be mature but man that really hurt me.