No. I can't be somewhat close with a guy without wanting him to fuck me. I just hate the term "fuck buddy". It implies that only sex is involved, which isn't true. But, it's also not a bf/gf relationship. It's hard to explain.
I know what she's talking about as I had friends who were the same way. They were basically in a relationship but they just didn't want the title of being in a relationship because they felt that they would have to go by certain standards and expectiations by people around them, and psychologically they'de be tied down to that other person.
That's all in your mind, you weak willed motherfuckers. Who's fault is it that you feel the need to go by other's expectations/ones you've made up? Yours.
"OMG, she's my girlfriend and now I'm psychologically tied to this person~!11!!!!"
Unless you are fucking other people at the same time, it's the same goddamn thing.