Alright,
First of all this needs to come from the horse's mouth. I'm an ENTP. And there is nothing worse than someone putting me under a microscope. I see the world full of possibilities, and hate cultivating weaknesses of others. I'm aware I have problems and I'm aware of everyone else's problems. I'm intereseted in things that generate possibilities. And I like girlfriends that are practical and creatively stimulating. Ex. I knew a girl that barely talked but her eyes spelled the word PASSION when she looked at me (like those puppies you see on tv, but with more of I want you aggressive look) She was very lustful and that was enough curiousity for me to keep her around. There was a another girl I dated that was very practical, for example she would laugh at me when I flirted with her (and found her even more funny that way) and when I was lost (such as taking 10 min to pick a movie) she would just buy the movie ticket and hand it to me before I could make a decision. Here's an idea to get him back!! Leave a rose at his doorstep and write on it "Let's flirt and get hot tonight". See my dear, the problem is that things got very very heavy emotionally, he doesn't want that. Entps are idealistic people, they want you to act like the little innocent asian cartoon girl that has a lot of attitude and looks cute, while you say "do this for me". Somewhere along these lines of interest lies a person who stimulates idealism. In the sense that you cannot bring back happiness with seriousness. There is nothing interesting about opening up... seriously. It's all good the first time but after that it's too depressing. In an ENTP's mind, there is security with a girlfriend and then there is romance with a girlfriend. Security is stable but it's depressing. Romance is entertaining but it's unreliable. You need both. And security is measure by how long you've been together, not how you act. For example you may act carefree but be with an ENTP for 5 years and that to him is enough proof. For an ENTP and if you do that he will follow you till the ends of the earth (because he is idealistic too). So he really likes you but he wishes for you to act more blissful and entertaining. Because things might be getting to the point where there are too emotional and emotions are redundant in his mind. These are the biggest key words to keep stimulation at bay for an entp: Entertaining, practical, time, blissful. Entertaining and blissful = flirt. Practical and time = security. I also dated a very confidant woman once who always had a serious look with everyone except when I would entertain her. So I sort of felt like it was my duty to keep her that way, instead of her being so serious all the time. And when I got tired and pulled away, she would tell me she needs some love instead of telling me "what's wrong". Seriousness will poor cold water over an ENTP's enthusiasm, where as blissfulness will recharge them. Keep it interesting, don't flirt with other people other than him, though, because that will be the end of it. And also keep in mind that this should be natural, are you two a match? Because I don't think you should have to change yourself. It's easier if you find your complementary person then you have to try less, it's more natural and lasts longer. Hope this helps, take care my dear and feel free to ask me any questions. I would really like to help but it's gonna take a certain amount of carefree-blissfulness in you.