So, first off let me say that I'm sorry you have to go through this. My "Big ex" kinda put me through a similar situation. Not so much to the extreme as yours, but more so on the side of telling me one thing, and me finding out that it was the opposite. It's really up to what you want at the end of the day. People can tell you to leave or stay with him till their blue in the face, and it's what you feel in your heart that's ultimately going to be the decision maker. Personally, I'm a big believer in finding someone that will make you happy and treat you as you would treat them. I'm sure your boyfriend wouldn't feel too great if the tables were turned ya know? I believe that people won't change until they themselves are ready to change, if that day ever comes. Seeing as how this has happened twice during the course of your relationship, and with a confirmed reply email, I'd say this guy is going to fall under the "Unchangeable" category, and I foresee this happening again in the near future.
Now, I'm sure that this guy is nice and loves you and what not, but that still doesn't change circumstance. Now, I'm sure you're having that notion that he's different, or he will change, or maybe it's not that bad. But as a person who is neutral, and as a person who is looking at the situation from the outside in, I would say your best bet is to leave this guy and find yourself someone else. I know that this kind of relationship doesn't just go away, but I think in the long run you owe yourself to find something that won't leave you guessing at what's going to happen tomorrow, or the next day, or years from now. Early signs like this, especially within the first few months to a year kind of set the table as to how the relationship will go during the course of its life, so whatever you decide to do in this situation just keep that in mind. I hope this helps, and (whether you know the answer deep down inside already or not) I'm sure you will make the right decision for you. Good luck.