There is a short story, I think maybe by Milan Kundera, the gist of it is the main guy is a bit (in fact a lot) of a shagger who knows loads of famous beautiful women. Then for some reason he has to spend some time at a sanatorium or something and he tries it on with all the hot nurses expecting to get laid as normal- but to his horror they all reject him.
Then one day one of his beautiful film star mistresses comes to visit him, and suddenly all the women realise that he is desirable to her and so he must have something, so the minute she leaves life is back to normal and he's fighting them off with a stick again.
Kind of similar to a couple of experiences I've had where someone that you somehow knew wasn't interested in you becomes interested when they see you dating someone.