Then he says he only realised because the other Hugo -himself, sort of in a double-personality thing, standing in front of him- said:
Hugo2: -Hey, you're in your calzoncillos -underwear- Hugo!
Hugo1: -No, I've put my trunks on
Hugo2: -Look at yourself!
Hugo1: (looking down at his underpants) -oh! you're right, Hugo!
He explained this jumping from one position to the other, and said he'd told his teacher he had to go back to get changed, and explained how he'd realised. She'd made him repeat it afterwards in front of the whole class, and told him to tell his mom the whole story!
...And he swears there were two Hugos!