Under the guidance of retail's smoothest knight of the realm, Marks & Spencer became synonymous with sexy food and scantily clad saucepots (of all ages) in its clothing ads. And that's not changed despite the more austerity-friendly ­regime of Marc Bolland.

True, some of its models including Dannii Minogue got ditched last week, amid worries their lithe and limber figures were alienating the blue-rinse brigade. But new research suggests the high street giant should be turning the heat up an extra notch in its advertising instead of taking the proverbial cold shower.

A hard-hitting study commissioned for Channel 4's Sex Education Show revealed that M&S shoppers are twice as likely to be into group sex as the national average 10% at M&S, compared with just 5% for shoppers across the grocery market as a whole.

However, kinkiest of all is Iceland. Almost a quarter of its shoppers have had a threesome at some stage, which would perhaps explain why the frozen specialist sells so much party food and why the spring rolls and mini pizzas always seem to be on 'three for a fiver' deals.

Maybe that's why mums go to Iceland and why dads aren't always invited.