Alisha asked what period they had next although this was the last period of the school day. She brushed it off with a, "Pssht, I knew that..." when her crush walked by.
All you have to do is stick out your thumb, index, and pinky fingers and say, "Pssht!" whenever you see your friends.
You can do a behind-the-back pssht or an under-the-leg pssht, etc.
You can say it really long, like "Pssssssssshhhhhhht," usually by adding more s's and h's.
The pssht is kind of like Spiderman -- oh wait, except NOT! Notice how Spiderman doesn't use his thumbs, his webs come out of his wrist not his fingers, AND he doesn't say "Pssht."