It's wrong to use people. To take advantage of them. To knowingly do something that will cause another person pain.
But, some of us do it anyways. And our reason for it? "Why not?", "It's fun.", "They asked for it!"
Though in some cases, those may be legitimate answers, you're most likely just saying it because you feeling guilty and you know you've done something wrong. So, stop trying to justify what you know is wrong, with lies, and just do the right thing.
What if you don't know what the "right" thing is though? Right for who? You or the other person? Why do you always have to be the one to make the sacrifice, to be the "better person"? What if, just this once, you decided that you would do whatever you wanted, regardless of it's consequence on you, or anyone else?
In all honesty, you would probably feel amazing, free and finally feel accomplished in a way that you never thought was possible. But after that high is gone, after the moment has passed, you'll realize what you've done. And at that point, you won't be able to return to that high and you will never escape from the regret.
Now you're stuck. Deciding between the thing you want to do, and the thing that you should do.But why can't those two be the same thing? Why can't you pick both those options? If you focus on the benefits of the 'right' option, it may turn out to be the exact thing you wanted in the first place.
So, go ahead pick her, him, this, that or it. Just make sure it's what you really want. But if you're gonna do something, give it your best effort, dedication and commitment. Because in the end, a half-ass job is just as good as not trying.