Matthew reached the spot where the two of them had been conversing, the blonde still looked a bit scared. While Niko started talking to the new boy that had come up, Matthew decided to get over his weird anxiousness that came with talking to other people and said, "Hey um, you doing okay? Your eyes are as big as saucers." 

Having been too far away from the two originally, he hadn't seen Niko's shirt move so he didn't know what was actually concealed in it, but that may have been a good thing.