make (a gesture) at (one)
To create a sign, symbol, or gesture with one's hands and display it in one's direction. The student was sent to the principal's office for making rude gestures at the teacher from the back of class. You do realize that you look like idiots making gang signs at each other like that, don't you?
make something at someone
to make some sign or signal at or to a person. Carlo made a sign at Bill, who seemed to know just what to do. Jimmy made an obscene gesture at me!