Why am i the other girl all the time?

ive been in relationships so dont think ive never been in one..but theres been a lot of times where i talk to a guy and we click or wutever but then when it comes down to going out they just wanna kick it and not go out...so that tells me right there wut they really want. and then i find out that they have a gurl or they like sumone else way more...am i not good enough or sumthing?