Here's the thing. I'll assume you're all adults. You talk to adults like an adult. You DON'T just take all your marbles and go home. Then you're no better than him.
Calmly, but firmly, express to him that what he did was unacceptable and will not be tolerated.
You have NO IDEA how he will react to that.
It could be "Screw you. You're fired." (In which case, the end result is the same. You're out of the band. No big deal.)
Or, on the other end of the spectrum, it could be "Dude, I'm SO SORRY. I just got so excited that I wanted to get these songs done. It won't happen again. Lemme buy you a beer and let's talk about some of your ideas."
Very likely, the truth will be somewhere in between.
But TALK to the guy. Sure, what he did was stupid. But if I kicked to the curb every friend of family member who ever did something stupid to me I would be very lonely. Same goes for me. I need a second chance from time to time.
Be the grown up. It may get you nowhere. But it may get you a continued project with more collaboration and friendship.
Seriously, just quitting makes you no better than him. A grown up conversation is needed here.