Should you ever invite an ex to your wedding? The news that Prince William and Kate Middleton have invited no fewer than six former partners between them to their nuptials, including William’s generously monikered Isabella Anstruther-Gough-Calthorpe, has set the hand-wringers off.

Aside from the fact that I believe everyone should have at least one Anstruther-Gough-Calthorpe at their wedding -not least so that they can feel the calligrapher really earned their money -my first response was: What’s the problem? Inviting your ex is as traditional a part of the Big Day as bridesmaid meltdowns, dad dancing, and wanting to punch the groom because your wedding car never turned up.

As Kate Middleton has no doubt recognized, having at least one exboyfriend at a wedding shows the assembled guests that you are not simply clutching at the first partner to wave a ring in your direction. It suggests you are, if not mature and worldly, then not so naive that you are likely to collapse into giggles or bolt for the door. It also shows that your exes are actually still alive, and not chained in a dungeon lined with pictures of your happiest times together. Ideally, any former beau of the bride should be incredibly handsome, murmur “doesn’t she look beautiful?” at appropriate intervals and look on wistfully. Or, even, as happened to me, mutter drunkenly to your mother: “It should have been me” (this is the actual trump card of ex-at-your-wedding behaviour). The effect is entirely negated, however, should your mother respond by clutching him tightly while wailing: “I know.”

For the groom, exes should outnumber the bride’s by a ratio of two to one -so William’s four to Kate’s two is, of course, acceptable. An entire rugby squad of ex-girlfriends does tend to send out the wrong message. Any female exes should be entirely eclipsed by the bride. Although perhaps not as per the immortal best man’s speech from Four Weddings and a Funeral: “When Bernard told me he was getting engaged to Lydia, I congratulated him because all his other girlfriends were such complete dogs” -pause -“although may I say how delighted we are to have so many of them here today.”

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