Either this idea was made years ago or I had the idea years ago, I'm pretty sure the former. (Can't really remember, but it's very familiar to me, think I can vaguely remember visiting a site like this in the past.)

Personally I can't imagine ever using something like this, not sure if that's because the concept is flawed, or because of my personality, or perhaps it's simply a service aimed at school crushes rather than adult life. But would be interested to hear from someone who thinks the opposite.