With your pinkie
That is correct because I have a friend from china and that is how they flip someone off in our school. So nobody knows what we are talking about. Its great fun and the best part is, not a lot of people know what we are talking about. Lol.
Your son is partially right. The sign we use for saying okay with our fingers is the way you flip someone off in China.
Well I heard it was the pinky too but I also heard that you extend the pinkie, ring finger, and middle finger then you use your pointer finger and thumb to make a circle. Its like an A- OK sign
By holding up you middle finger only and clenching the rest of your fingers in a fist