So this chick was flirting with this dude, they were the center of attention of all people around. He was leaned back to the wall and she was between his legs in front of everyone. They were really close. So everyone's going back and forth here, I came up, stand there for a few seconds, I'm the tallest of my group, she seems to notice me.
I was in my school's uniform and she noticed that too:

HB: So you're in your school's uniform?
Me: Yeah
HB: What school is that? (I'm pretty sure she already read the name on it)
Me: X Christian School
HB: So you're christian? Ha, christian are all pussies.

I just stand there being negged by this chick, and adding insult to injury she was ugly as fuck too. Standards these days.
So anyways, I didn't know what to say and just stood there.

In what ways could I've come up with something clever that:
A) wouldn't give the guy room to "protect" his girl
B) would alpha me by saying something that saved me
C) would make me recuperate without giving in to her provocative comment

I'm not Christian, I'm just in a Christian School. In my society, being a christian makes you a pussy because they don't do nothing therefore have no game.

"not as a big of a pussy as you are"
"this pussy will kick your fucking ass"
"careful or ill pimp smack your with my bible"
or just carry on the conversation like nothing happened. i think this would have worked very well on that particular girl seeing as she was an attention whoreing cunt.

Ok mate this will sound harsh.

You are a pussy. If you were not you wouldn't have come here telling us about your problem. You would have just said to the girl "Yeah sure" without thinking about it even a tad bit.

Work on not being effected by random people's comments and not to define your self worth through others opinions but your own.

Let me give you an example. A guy in the gym said that my arms look like shit. Since I can't care less about his opinion (I'm quite happy about the way I look) I just said "Ye man". This was in a group setting. He looked like an ass afterwards. He started apologizing that he was just joking etc. while I genuinely didn't care because his opinion didn't matter in the first place. It was funny tho

Maybe witty comebacks also work, but I personally never use them, because it's try hard and takes too much energy away.

that wasnt a neg

This is so sad. As ptown said, it's not a neg. Neither is it a shit test.

You said it yourself. She's fat and ugly. A proper response: "That's cute but I don't really care what fatties think about me." Who cares about the guy? Do you think he'll get up and punch you in the gut? With your height, you're practically a tower. He'd probably be afraid to stick up for his whale if you put up the proper frame. Worst case scenario he mouths you off. "Aw, the cute couple is mad " Then proceed to walk away.

Whenever I get socially challenged, and I cannot think of a good response, I just look at the person who told me for a few seconds, in complete silence, with all the other people around me waiting for my response, and then...I continue what I was doing before.
I know it's not as good as you might've thought, but it's effective in making the other person feel awkward and bad about what she/he said.
It works wonders, but it's best if you simply don't care.
You're untouchable. Act like it.

Yes it is true. I've struggled with this forever. I just don't know what to say in these kind of situations. I occupy myself with all the thoughts of what they said and trying to come up with something that will get them too but most of the times I really don't know how to react.
Thanks for the help guys, I think I have a line where to start now. I think it's just getting my head into the game.

Your problem here is that you cared about this. You could've just looked at her like "You're weird" and continued talking, or even just ignored her statement completely because it doesn't even deserve recognition.

"Cool" without the slightest form of investment would've also been fine here, as if you hardly even acknowledged her. Then you would immediately stack forward with something new to say. But it has to be done like lightning, because you care so fucking little about her statement that you don't even register it.

It's surprising and you'll have to get used to not visibly showing surprise even if you are surprised. There are some good suggestions here, but I would avoid at all costs getting into an insulting match with her or calling her fat etc... that's just shows you'll engage on her terms - you should engage on YOUR terms, take the higher road and completely disregard her- make it seem like what she said had no effect on you (even though it seems like it did)- and distinguish yourself as a high value male ... eventually you'll get more comfortable with being insulted outright (it usually doesn't happen so brazenly).

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Preston's Game Log - Please critique

Wow!!! im just new here and I always have that problem... I'll just ignore then... thnx.