There are some unexpected responses on here!
Op, as far as I'm aware, it's very normal for people not to use other people's treats and presents without being asked to share.
If I receive a nice box of chocolates from my friend for my birthday, my DH/DCs just wouldn't consider opening it, at least not without asking me or hinting heavily that I really ought to be sharing them!
If I have a bar of the chocolate I like (I don't like many) in the cupboard, the family know why it's there and they would have to be pretty mean and selfish to eat it.
When my DB bought me some fancy wine for a special birthday, my ex opened it when I wasn't there. It was utterly selfish and felt like he'd done it to send me a message - he'd figurately pee'd all over the special moment I'd planned for drinking it.
Your DH is thoughtless, thinks he can take things other people were looking forward to . had bought specially, but not share his own stuff, then lies about it afterwards. All bad enough, but you've spoken to him and told him it upsets you and the children and he continues to do it. I don't understand how anyone can think that's OK.