In certain martini venues, the “two martini rule” is observed.

Once you have consumed two, you must move on to a soft drink, such as wine or a gin and tonic.

The reasons for this are obvious and I try to adhere to this rule at home.

The rule is defended most enduringly (and elegantly) at Duke’s Bar in Central London, where years of experience back up their assertions.

Indeed, years of research by the author to triangulate research reveals that indeed, the rule is there for a reason.

Nonetheless, we still regularly encounter resistance from drinkers who have finished their second martini and, sacre bleu, would like a third. They must be saved from themselves, forewarned – but also comforted and protected if they proceed regardless.

They will regret their choice in the morning, but given the beauty of the drink, we cannot blame them.