This is the kind of thing that happened to me a lot in school, especially middle school. I guess it's mild bullying, because simply talking for us SA people is so torturous! Anyway, popular kids would for some reason start talking to me with an amused look on their faces and their friends snickering in the background....I never really understand it. I think they think its funny. They want to know what the "quiet kid" is going to say if you confront them.
One thing that really made me feel terrible in middle school was those idiot boys who, for no reason, would approach me in the hall, a group of friends behind them. "Will you go out with me?" they'd ask, cracking up even as they said those words. I don't even think they knew my name. They just wanted to see what I would say.

I always said nothing and walked faster, but it nearly killed me inside to know I was the butt of their inside joke.
That might not be what you're talking about, but even if what the "cool" kids said to me was completely harmless, I would still walk away blushing like mad. It's because I felt inferior to them, and they know in their minds that because I feel inferior, I am thus making them superior. And in the end, I always feel like I've said something stupid and dread the next encounter.
I don't have much advice, other than to try your best to boost your confidence when you are around them. Just because they are deemed popular doesn't make them better than you in any way shape or form. In fact, look them up in twenty years and there's a good chance you'll be more successful! :wink: