My OH did that the first year my mum refused to do my stocking - I told him it was now his responsibility and as he forgot, he filled the stocking with fruit, nuts, and the pastry brush from the kitchen draw

Got my revenge this morning, its his birthday and he hasn't decided what he wants yet so I haven't bought him anything. So I went to the shop and got him a mars bar from the dog (wrapped up in several layers and a tupperware box to make it look interesting) - as he opened it he said "I bet this is something that's already mine that you've found lying around the house" so hopefully he was pleasantly suprised that the dog had bought him a mars bar.
To add to that, yesterday when I slyly finished off his secret pack of ginger cream biscuits, I saved the last one, wrapped it in clingfilm and wrapping paper and presented it to him this morning.
I'd like to say he was pleased....