Okay, so like many stories start there's this guy. I've known him for a while now, all my friends are guys so he's a friend of one of my best friends. Anyway at a party we started making out, totally not my style, and now he's like completely in love with me. At the drive-in the other day we were rounding 3rd base... I really like him, he's like the class clown. Always center of attention at like a party or something, and I'm completely the opposite. I really like him, but I don't know if I'm ready for something like this.
I like him, and I told him I wanted to take it a bit slower, and he didn't have a problem with it.. But I'm kind of nervous about what might happen if we got into a situation like at the drive in, I'm the kind of person that thinks things through before I act on them.. I don't know how it got that far in the first place.
So I guess I'm wondering what I should do, or say, if something got heated like that again. As I learned, in a situation like that guys can't be the one to say no... it doesn't turn off like that.

Veronica,

So you know only you are responsible for yourself, right?

What's to be afraid of? If you push him back and he doesn't want to back down its not right.

Don't let the desire of being liked or wanted be with another be what drives you sexually. Don't let fear be what causes you to allow another to go beyond your comfort zone.

A woman who takes control of her sexuality is in a powerful place. This doesn't just mean you act on your desires... it means you hold back when you are uncomfortable or uncertain.

So... don't expect any other person to make the right decision for you. Its your choice to make. If the other person is offended or disappointed, it's a bad fit.

It can be that simple.

Just don't let it get to that again and you have nothing to fear

if you said no.. he wouldn't do anything to you.. but if you said no and he keep going then.. he not respect you and if he not respect you then do you think that he even like you or he just in it for sex ? ^^ you are the one that make the decition you decide what you want or how thing will be ^^

THINK ABOUT IT ^^

I am concerned about the clash in the personality traits. Others have given you great advice on the rest of your question.
I am picturing you 20 years from now at a party with him wearing the lampshade, and you cowering in the corner in embarrassment. You are a planner so look ahead and try to decide if the basic differences can be worked out. Decide on this issue first.
People don't change so what you see is what you get.

You've posted this question and it seems like you may feel a tad pressured if things 'got heated' again. Simple.. don't do it. Have respect for yourself, there is nothing less serious than a girl who gives in too easily. You make the decisions.