[Sundae]

Sam - it's the thrill of the chase.
My Evil Ex used to reel me back in every time with this sort of attention. And after a while (the timescale went from months, to weeks, to days, to hours) he'd have what he wanted and switch it all off again. Or generally transfer it to another woman. In fact towards the end he didn't even wait until I'd left his flat before starting gooey conversations with "just a friend".

I don't think he will change his plans if you're softening. He'll find it more useful to talk you round. If you are capable of issuing an ultimatum and sticking to it you might get rid of him sooner rather than later. But don't expect him to take no for an answer. He'll more likely let you stew for a few days then phone up pretending the two of you were still on for meeting after he had seen his son all along.

I could be way off beam, but his behaviour just sounds so distressingly familiar to me.