When a 5 yr old explodes....

Today should have been a very easy day for me.. I only had my 17 month old niece, and my own children. Piece of cake compared to what I'm normally doing.. At some point today, my oldest son told me that someone had drawn on a chair in the living room. Hmm... It wasn't just a slip of someone's pen, or a teeny little scribble. It was about 6 huge black lines on both arms of the fabric covered chair. Long lines too, from the front to the back. It looked like someone was trying to create their own plaid design, and got caught in the middle of it.. however, I totally missed this happening, and figured my 2 year old had been up to no good.
When I asked my son who did it, he said "I did, but I don't know why" He was just sitting in the chair, with a pen, some paper, and an apparent need to ruin my chair.. I kept my cool, surprisingly, and told him that he's not to draw on the furniture, only paper.. same schpeil that I've been giving him since he was 2. This did not go over well with him. He lost his shit with me, told me that I should say I was sorry for yelling at him ( seriously, I didn't yell.. ) He then went on to tell me that I was a bad mom for looking at him the way I did.. and that if I didn't apologize that he was going to run away, and that he didn't love me, and that he hated me.. WOW! That was pretty much how I reacted. I'm thinking that he was so upset with himself, that he took it out on me, because REALLY, there was no yelling! And nothing nasty about it. Perhaps the look of disappointment on my face when I discovered that he had done it, was just too much for him.
It made me feel like a heel, although when he went on about how he would go live with his grammie, I did get a little chuckle. He told me he was going to walk there.. but that I would have to give him directions because he wasn't sure which left to take!!
He eventually calmed down, and has been apologizing to me all afternoon, about saying those mean things to me. At least I know this is a child that isn't going to internalize much! jeez.. I didn't bother to mention to him that his grammie is getting us a new chair for Christmas, and we probably won't keep the one he drew on.. I figured he should worry about it just a little!