He is shown several possibilities that range from £50 to £150 in price, the more see-through, the higher the price
He opts for the sheerest item, pays the £150 and takes the lingerie home.
He presents it to his wife and asks her to go upstairs put it on and model it for him
Upstairs the wife thinks 'I have an idea. It's so see-through that it might as well be nothing. I won't put it on - do the modelling naked, return it tomorrow and get a £150 refund and keep the money for myself'.
So she appears naked at the top of the stairs and strikes a pose.
The husband says
Spoiler:
