This is not a marriage! He is doing exactly as he wants, whilst you are planning for the future and he knows this, so he spends his money knowing you have the financial aspect in hand.
As for the BBQ invites, either tell him he shops and cooks, or as Maw says, tell him you have other plans for the day, so he can entertain on his own.
I was married to someone similar, and the relief when I 'escaped' was immense.
I think you know what you need to do, it is having the courage to go through with it, which I understand completely.