One solution would be to buy the DVD and then hold a potluck where you invite a few friends over to view it, strictly privately. Since the cost of a DVD here in the US is often only about twice the price of admission to a cinema (sometimes even less), you're no worse off than if you and your spouse/partner went to see it. Plus you own it...AND, if it's really good, some of your friends might buy it or recommend it to their other friends. I don't know if the prices work out as well in the UK.

This works best if you have a big TV, which I do....