I feel that no one is replying because there's nothing we can do, and there's not really much you can suggest. I assume you're in school? If that's the way he wants to react, that's his choice. If you feel it's not justified because of whatever reasons (such as, you always tease him or whatever) then just tell him. If he wants to rant, leave him to it. Don't tell the female friend what he said because either a) she'll ask why he's not talking to her or b) it'll be pretty obvious when he's ranting at her and c) it doesn't really matter actually. It's a shame when friends fall apart, but he'll probably get over it. Don't let it ruin your day.