Even if I could plumb your ex-boyfriend's mind for the answer, I wouldn't tell you. Because you don't get to know that. You are his ex now; that's what the term means. You've got no more right to know his thoughts, dreams and motivations than any Chinese dentist on the face of the earth.

The fact that his terrible excuse for a conspiracy can get a reaction out of you at all means one of two things:

1. You aren't really broken up, you both know it, and this is just part of the cycle of your drama-fueled jalopy of a relationship. It's more common a phenomenon than you'd think. Essentially, your relationship is attempting suicide just for the sympathy (or worse, out of boredom). If this rings true, my advice is to RUN FAR AWAY. You're in an unhealthy relationship with someone who enables your bad behavior; you've got a much better shot making the breakup stick and focusing on why you care what an ex does with his junk.

2. You really are broken up, but you've failed to move on. Maybe he made up the fake girlfriend as a hint that you should scram. Maybe he did it to try and make you jealous to win you back, because he thinks the world works like a Disney Channel show aimed at tweens (which it often does). In either case, my advice is to RUN FAR AWAY. All you're doing is prolonging the pain associated with a breakup. Whatever it takes, whoever's help you need to do it, make a clean break and cut off contact with the guy.

As you can see, all signs point to "stay out of his life," which isn't to say that he's right, just that you were wrong to think he deserves to take up time in your head or space on your calendar. Leave the chump to his own devices.

Otherwise you're choosing to take the most difficult and painful path before you, and you've got to ask yourself whether you're doing so out of stubbornness, habit, or plain old goober-ism.