Especially for those guys here, lets say you're into a girl, and she isn't really into you but you think she is.

What is the best / most comfortable way to be told this fact?

It's always such a tricky conversation, and I hate leading people on.

Whatever you do, tell the truth. Many moons ago, my fiancee told me she was going to visit her mom when she was really going to visit her ex boyfriend; she never came back. Another told me she was a lesbian and started dating another guy soon after we broke up. Another... while planning our wedding, I found out she was still married to her 'ex', and when I told her she had to divorce him in order to marry me, she kicked me out and moved him in. Another told me she was "yours, only yours, and yours forever", two weeks before getting involved with someone else and four weeks before I found out about the other guy.

So, yeah, be honest. Because I hear women all the time wondering where all the good guys are... We're hiding behind high, thick walls that No One will get through again.