How do you know when you're in love? Perhaps it's when your bra magically unhooks whenever the one you love is around.

The Daily Dot reports that an intimates line called Ravijour has a product for women they'll never be able to take off. It's the modern day chastity belt, and it's a bra called the True Love Tester.

Ravijour collaborated with "human sexuality specialists" in Japan to create a "revolutionary new bra that knows how women truly feel."

A special device measures a woman's heart rate, so if she's sufficiently turned on, the bra will unlatch - which then draws questions about whether a woman needs to really be in love before having their bras unlatched. Needless to say, it would be advisable that no woman wear this bra while exercising.

Find out more about the bra in the video below: