Dress that turns transparent when aroused

Daan Roosegaarde from Capetown has designed a dress that combines technology with social fashion.
A dress that becomes transparent when the wearer gets excited.
The idea itself is pretty exciting, though woe betide the man's feelings if the dress stays completely opaque.
"Darling, aren't you pleased to see me?".
"Yes, it's just I have my pacemaker turned down to keep the excitement from wearing the battery out!".