Meatballs,
You don't "turn" gay. It doesn't happen. Lack of female contact or no, you don't "turn" gay. I really don't understand how Notseingme is in the same situation, and I really don't see how his "advice" was really consequential.
People fall in love with people. I have fallen in love with women before. That doesn't mean I'm "turning" straight. I can tell you, that I've never had sexual attraction to a woman. For me, love with women is very fraternal. What you describe is something different.
What you don't say is: Have you ever had thoughts like these before? Have you ever had thoughts like this for a woman?
I'm not saying you are or are not gay. I really don't think it's important whether or not you are gay. I do wonder, though, if you always just *assumed* you were straight, because that's what you saw as "normal." If you have never had these thoughts for a woman, it could be that you are indeed gay. If you have had thoughts like these for a woman, it could be that you are indeed bi. It could also be that you've found the one guy in the universe that it's even possible for you to have these feelings for. In that case, i don't think there is a nifty neat little label to hang on your head.
What I'm saying is: Notseingme's advice seems to be "just ignore it." That's the worst advice ever. Instead, use it as an opportunity to reflect on yourself. Ask yourself questions about your past, and where you see yourself in the future. If you genuinely have romantic feelings for your friend, try and find a way to talk to him about it without expectations. He may not take it well, and it would end your friendship. He may have the same feelings as you, and you may be looking at a beautiful partnership. He may not have the same feelings as you, but respect you for coming clean, and continue your friendship with the understanding that it will always be platonic. NOBODY can tell you that this WILL ruin your friendship - and if they do, they're spreading needless fear.