We're not together because you have a girlfriend and I have a boyfriend. I know people will judge this particular reason. I was once told that having feelings for another person while in a relationship is wrong. My response to this is simple, it's not wrong if you don't really act on your feelings. Feelings cannot be controlled but your actions can be. I did everything in my power to not act on my emotions and when it started being too heavy for me to handle, I told my boyfriend about them. And though I know he felt bad about it, he still accepted me. He stayed with me. He said he loves me and that my feelings for you changes nothing. Which brings us to reason number 2.
We're not together because no one can love me the way that he does (admittedly, I don't know how you are as a boyfriend. But I know this to be a fact). It sounds selfish and unfair but it's true. We're not together because I would rather be with someone who loves me more than I love him. I'm too much of a coward to start something uncertain with someone with a personality as volatile as yours.
We're not together because I'm not your ideal person and you aren't mine. You're immature and selfish and controlling while my boyfriend is mature, loving and though he can be overprotective he knows his limits. I, on the other hand, am probably the farthest thing to your ideal girl. Let's leave it at that.
We're not together because I feel like my heart breaks when I see you, while my heart soars when I see him. He makes me lighter while you make me feel like the whole world is ending. You bring our the worst in me while he makes me want to be a better person.
I have a few dozen reasons why we aren't together, but this one is probably the biggest and most important one. We are both too afraid. I'm too scared to leave my comfort zone and you're too afraid of rejection (assuming you have feelings for me the way my desperate and stupid heart is telling me). I'm too afraid to fight and you're too much of a coward to even start anything. We are both struggling with our inner demons and no matter what happens, we'll both end up losing. We'll lose ourselves and we'll lose the people that love us. This is why we're not together. Because you and I, we were never meant to happen.
And now, when I think of you, I just try to see you are a new challenge. You are a hurdle to get past. You are a test. You are fate trying to shake my faith in love. You are the new phase that I've trying to move away from, the self destructive phase. You are bad news waiting to happen. You are heartbreak on steroids. You are, quite possibly, the biggest mistake I could ever make. You are a phase, and I think it's time that I outgrow you.