the gay kid in my class has a crush on me but im not gay?

Just turn him down like you would any other girl you are not interested in. Be nice about it but also clear. And tell him sooner than later because by you not saying anything he might think he has a chance. 

Talk to him and let him know you are straight and can't see him that way but you could be friends 

Just tell him that you're flattered but that you're not gay or bi and so can't feel the same way towards him.

Everyone has someone who they desire but can never have.   its just how it is.

That's not actually a question, Elliot.

However, even though you muffed the Jeopardy "in question form" requirement, I'll offer you a bit of advice.  The kid doesn't know you.  He just thinks you're dreamy for some reason.  He probably doesn't understand it any more than you do.  He can't help it.  In any case, he's no threat to you.  It's not like he's going to assault you or anything.

Face it - what you're really concerned about is that everyone in school will consider you "gay by association".  (There's an ancient rule among boys & men that, if you don't punish gays everywhere you find them, that YOU must be gay YOURSELF...and should be punished, too.  That rule's been shaping Western society for centuries.)  So what you're really afraid of is being ostracized and ridiculed by your classmates.  THAT'S what's worrying you - not this dumb kid.

It helps to know what your real threat is.  If you properly identify the threat, you can deal with it more effectively.  It's not the kid - it's the stigma some of your other classmate will try to hang on you.

Here's how to handle THAT:  You have other friends.  Don't make a point of it, but in conversation you can let them know that this guy seems to have a crush on you, and even though you don't swing that way - being a nice guy, you can see it's not something he's chosen to do just to annoy you...so why be mean to him?  

Let your friends know (especially the girls) that you're going to be nice and let him down easy while making sure he gets the message, and just put up with him till his fixation on you passes.  By putting that word out early, you'll foil your frenemies who would love to make you gay-by-association AND you'll impress your more compassionate or progressive classmates.  It's a win-win. 

Crushes at your age are common. And usually frustrating. Be kind. 

So? A crush is a compliment?

Tell him you're straight and that although it's okay to be gay, you're not.  Let's be just friends.  

Give him a bible where you have highlighted the verses about homosexuality. 

That can change, Elliot.