** All along it was a fever
A cold sweat hot-headed believer **

It's about two friends who have tried to ignore the chemistry between them because they can't really be together (he's in another relationship).

** I threw my hands in the air, said show me something
He said, if you dare come a little closer**

Finally, she gives in and says, "okay, what is this?" He responds by basically telling her he wants to risk it and pursue a physical relationship.

** Round and around and around and around we go
Oohhh now tell me now tell me now tell me now you know

They have this forbidden relationship, and she's wondering if it's made him see her differently.

** Not really sure how to feel about it
Something in the way you move
Makes me feel like I can't live without you
It takes me all the way
I want you to stay **

She tells him that she's not sure that it's just a physical attraction anymore. She's in love with him and wants more.

** It's not much of a life you're living
It's not just something you take, it's given **

He tells her that she's not open to emotional relationships and that's the only reason she feels like this about him, because he's the only one she's let get close to her.

** Round and around and around and around we go
Oohhh now tell me now tell me now tell me now you know **

He's saying that what they have is just physical, not romantic. He wants her to understand that.

** Not really sure how to feel about it
Something in the way you move
Makes me feel like I can't live without you
It takes me all the way
I want you to stay **

He's torn between knowing that he should let her go because he's not willing to give her more and wanting to continue the intense physical relationship they have.

** Oohh the reason I hold on
Oohh cause I need this hole gone
Funny you're the broken one but I'm the only one who needed saving
Cause when you never see the light it's hard to know which one of us is caving

She's hurt by his response. She tells him that the reason she's stayed with him is because of the emotions, not the sex, and that he's got a lot of nerve telling her how to love someone when their relationship is proof that he's the one that can't really love his significant other (hence, he's "broken"). She's calling him a hypocrite.

** Not really sure how to feel about it
Something in the way you move
Makes me feel like I can't live without you
It takes me all the way
I want you to stay... Stay...
I want you to stay, Ooooohh **

She's saying that she doesn't know what to think about their relationship now, but ultimately she loves him and will take whatever he's willing to give her.