So after all of these years I have finally figured out why Mario and the Princess are still in love. They use the Nintendo Love Tester, duh.
The original device was created in 19(69) by Nintendo, ha. Who would have thought, long before the video game kings were kings they knew a think or two about geeks and love. Apparently each lover holds a ball, and the doo-hickey will yell you and your lover how much you love one another.
Still serious about this, want to buy one, lol, you can! They are being remade by a trendy little shop in Japan. Read more to grab the link.
Back by popular demand, the Nintendo Love Tester is a groovy remake of the version that was first released in 1969. A way for shy couples to test how passionate they feel about each other, both partners just hold hands and each grasp a ball. The tester then gauges how stimulated they are when they kiss by using the same kind of technology utilized with lie detectors: the higher the passion, the more your hands sweat, the more the dial reacts!