"I'm not gay."

This is a common phrase said in today's society, especially amongst teens.
It's so common, that it's often glanced over. (Like many things.)

So, let's just take a moment and backtrack. What does this phrase even mean? As with any phrase, it depends on the context. Well, "I'm not gay" is often said in a derogatory tone in response to a stereotypically "gay" thing. That was a weird sentence. Basically, people say "I'm not gay" in response to things they think are gay.

Note that the following refers to "you" a lot. "You" isn't anyone specific, it's just someone who says "I'm not gay" in this type of situation. For example, if the following conversation hypothetically went down,
{Person 1:} "Do you like this pink sweater?"
{Person 2:} "Ew, no: I'm not gay!"
Then I'm referring my anger at person 2. (sorry if my example was stupid, I couldn't really think of anything specific, but I think you get the general idea)

My problems with this are:
1. What the hell is wrong with being gay? People try to be open minded, or at least a good number of people do, and they claim they have no problem with different types of sexuality. But when they themselves are the person who may or may not be gay, it's suddenly a huge fucking deal. People are okay with other people being gay, but not with the idea of themselves being gay. Don't get me wrong; it's absolutely fine to be confident in your heterosexuality. But there's no need to be offensive about the idea of being gay. By saying "I'm not gay!" in a negative tone, it's like saying "I'm not gay because that's gross!"
2. No one said you were gay. Literally the only person bringing sexuality into the conversation is you. Even if someone else had brought it up, what is sooo offensive with the possibility of you being gay? Anyone can be of any sexuality. There is no way of telling, which brings me to my third point:
3. You are stereotyping. It's just plain offensive and wrong. I'll just leave it at that.

• Yea, I'm probably overreacting. But I'm fine with that. I'd rather have something to scream about than have nothing to say. I'd rather make a big deal out of something than not care about anything. 

• You might say I'm reading too much into this, and honestly, you're probably right. Well, oops. Am I supposed to apologize for that?

• Why do I get offended so easily? Well, because I'm passionate. And there is nothing wrong with that.