Why is your ex-bf still treating you like his gf? Because you're treating him like your bf. You take a break (with no closure)... and then go out to dinner with him and spend the night. That's a relationship. I bet he thought that perhaps the break was over and invited you to dinner to test the waters.
If you want him to stop treating you like his gf, then break up with him. Do it gently and kindly, of course, but this in-limbo/halfway thing doesn't seem to be working for you.