A 77-year-old shopper was left humiliated when a supermarket cashier refused to sell him beer because he was with his teenage grandson.
Edward Lamb went to the Co-Op to buy a case of lager with his 13-year-old grandson Max.
But he left empty-handed because the sales assistant refused to serve him unless Max could prove he was over 18.
Mr Lamb, a retired purchasing manager, left the store in Bishops Lydeard, Somerset, and then walked back in without Max and they still refused to serve him.
He said: "The thing that I find most offensive was that she didn't speak to me and spoke directly to my grandson.
"I said to the girl 'It is quite alright he is my grandson, he is with me' and she said 'Well, I can't serve you, then'; so I asked Max to leave the shop and said I'll buy it on my own, but then she said I can't serve you because I know he is outside'.
"To me it is just pathetic, no common sense."
Mr Lamb wrote to the Co-Op after the incident last month and was told the sales assistant believed he was buying the beer for his grandson.
The company added that members of staff have been trained to err on the side of caution.
Mr Lamb added: "The thing I find ridiculous is the assumption I am going to give it to him. I might just as well go into the chemist to get my prescription and be accused of drug dealing because I am with my grandson."
A Co-Op spokesman said its Challenge 25 policy applied to anyone with the purchaser.
He added: "On this occasion, the customer's grandson was unable to provide proof of being aged 18 or over, and so the sale was refused."
