In the movie "He's Just Not That Into You", a couple of gay says that the sign is different between straight and gay people. For gay people, it only takes us 3 seconds of eye contact to determine if both people can hit it off, and 2 seconds for us to decide that we are not a match. So much more simpler then our heterosexual counterparts. I guess gays all over the world are alike, it's all about the sex for us.
But what the movie said about strung out was very true. When you really like someone, you'll make an effort to date the person. You'll hope to see his number everytime your phone rings, that you'll bring out the person's name in any random conversation. You'll wish you could write a song about that person. That's the rule, the sign. But consider this, that if you let this feeling simmer, allowing it to sink in without taking any action, that you allow the longing for the person to torture you emotionally. After a few weeks, you'll realize that the longing has subsided, or that another person is occupying your thoughts, you realized then that you're just not that into him afterall.