While you're boiling over with anger, he's in shock. The way he sees it, he didn't mean to deliberately hurt you: he thought you'd find it funny as well to hear for the hundredth time how you were spitting out seaweed for days after your water skiing lesson...
Not for one minute did he realise he was upsetting you. He now sees that you're not laughing, you're paranoid and sensitive...basically, you're blowing it all out of proportion! Well, what does he expect when he doesn't apologise for hurting you? The worst aspect of this situation is that even if he did behave like a jerk, your friends will most likely take his side, given the fury you unleash on him!
A better approach