Mark is adamant they can. ‘Men wear diamond watches and bling earrings – this is no different,’ he says.

He advises users shave the hair before applying the crystals, or for the ‘very hairy’, a judicious waxing or laser session could be necessary.

For those feeling understandably reticent, Mark insists it’s not only the nether regions that can be decorated with crystals.

He wears his own on the left-hand side of his abdomen, while others use the crystals to adorn arms, chest or back.

‘Think of it just like a crystal tattoo – and it’s less permanent than a real one,’ he says.