Being rejected is never fun. Sounds like he just wasn't in to you and didn't have the decency to be honest and upfront. Ive met lots of guys like that and eventually just stopped having sex with someone right away. But even then there is still people out there who wait it out then suddenly lose interest when the thrill of the chase is gone.
Sue, openly in a vee with Nate (polysexual, many fwb) and Sam (Mono)