Thanks for all the details - it really helps to have the background information. (I didn't really think he was drunk, but I mentioned that because ESTJs do act bolder when drunk, as so many other people do.)
Even if he is a flirt, the fact that his flirting was so over the top, and that he still has the pig in the car, and that he values your opinion so much, leads me to believe that he likes you. The fact that he freely admitted that the relationship ended leads me to believe that he isn't making a move now because 1. he's still scared, or 2. he's ashamed of his previous actions. It's pretty typically ESTJ to be afraid to make the first move, and the semi-joking-flirting is probably the closest he can come to admitting he likes you. (It might be involuntary, really - most of my flirting is involuntary, but I'm not exactly an expert in good romantic practices.) Plus, there's the fact that he's already in a relationship... which is problematic, since, unless she's okay with the relationship being open (which I doubt, considering what you said about her), you can't make a move on him. Unless you, say, talk to him about the possibility of getting back together (and/or his mixed signals), and see what happens then.