My boyfriend has lied to me twice already, he doesn't know I know. And we've been together for only 4 months. I hate lies, so I want to break up with him, break his heart in a way that he'll remember not to lie.

So you want to hurt him? Sorry, can't help you there. Do you really think he'll care if you hurt him? He lied to you, so obviously he doesn't care that much for you.

The only one you're going to end up hurting in this is you, especially if you realize that the revenge you want so badly, had no effect on him at all.

Let him go, and let it go, move on and forget about him. You're giving him more power than he deserves, so why waste time and effort on getting even with him?