Just because they wear cat tails/ears/etc doesn't make them furs.
But I think the others didn't notice the fact that you saw them with facepaint as well.
I have a feeling it's like Mako said, they're nekoneko fans. In other words, huge anime tards.
I actually seen a kid at school. He dropped his backpack and a tail popped out. He saw It come out and got all wide eyed and dived for it but I got to it first. I picked It up and he got all embaressed and I knew he was a fur. We have been friends ever since.
P.S. Check out my rp for furs called Fur Camp