Here we go:
1. A four pack of beer. If the shopkeeper won't let you buy it you might just get away with 4 cans of shandy if you're over three and half years old. Alternatively, buy four cans of lemonade, wrap them in special paper and just enjoy that moment of satisfaction when his delight turns to despair.
2. Buy him a copy of Fifty Shades of Grey so he can fantasize that all twenty one year girls talk like Batman, drop their knickers at the mere mention of sex and are even prepared to swallow. Male bliss.