Well Shaz, just read this thread and wanted to post, can see you getting stronger and really feel for you that you've had so much crap from this guy.
I think you should put ALL his gear on the girlfriends doorstep, don't waver, your not doing anything illegal but you will feel much better for doing it, all his stuff will be out of your sight, to see it every day must be emotionally draining and it'll tell him that this time he needed, to see which one of you he was going to choose (!!!) has now come to an end.
FWIW - I also think that his ego will have been a tad inflated thinking that he has two women wanting him, he knows which he wants at the moment and I stress "at the moment", he is just a cowardly in ending your relationship. I really think you should take control, it is far better for you and your lovely little boy.
Lets face it, you have what he doesn't, your little boy every day, what's he got....NOTHING!