I'm 18 and my boyfriend of almost nine months is 19, and we are perfectly happy with each other. I would never imagine an emotional or physical relationship with any other man.
BUT, I find myself, well, attracted to women sometimes. But I've had a little "bi-curious" state when I was fresh in high school, and I didn't enjoy is whatsoever. I've kissed women, but I don't find the same pleasure as if I were to kiss a man. And whenever I talk sexually with a woman, I find myself feeling kind of, dirty, I guess you could say, and I just want to end the conversation immediately because it makes me feel uncomfortable. And this has happened even when I was single as well. So my question is, why do I find myself thinking I'm attracted to a girl even though I can't stand the thought?

Maybe you're afraid of your feelings so you can't drop feeling guilty.

You realize you aren't being fair to your boyfriend, right? You're "talking sexually" with another woman while in a relationship with him? If this were reversed I suspect you'd be VERY unhappy.

Well I will admit I did talk to a few girls a couple times while we were dating, but that only lasted less than an hour on each account because it felt to wrong, and that was early in our relationship. I haven't done it since. However when I was single, it has happened numerous times and I find myself with the same outcome, running away from the conversation. I do realize it wasn't fair, which is why I deleted every social site aside from Facebook so I would not, well, "give into temtptaion", because I don't want anything ruining our relationship. However, if I see a pretty girl walking down the street I feel myself thinking such attracted thoughts and what not. It's just confusing.

If you are confused about your sexuality you owe it to yourself, to say nothing of your boyfriend, to address it. Do you intend to perhaps marry him and THEN discover you are either bisexual or lesbian? And if you discover that you are, are you prepared to not act on the feelings?

You need to speak to someone.

I'm a female. I certainly enjoy the look of an attractive female but not in a sexual manner. Are you sure you aren't confusing admiring a woman's "style" with being sexually attracted to a female?