Two Quick Stories,
The first I was working in an office building as an engineer. I was between a support pillar and a cube wall, we had some cables for test equipment on the floor. This guy jumped at me and shoved. I stepped back a couple of inches to gain balance and slipped on a cable. I went down. Everyone was surprised including the guy who had made the shove. He asked what Happened???
I replied, I had three options, Go down and take you with me as the pillow. You get hurt. Take you down with me and I might get hurt. Or just fall and break fall and no one gets hurt. His reply was you actually made that choice in that short of time? I said Yes I did, so as to avoid hurting others. No one ever bothered with the fakes again.
Previous to working as an Engineer, I was a Manager / Bouncer of an Arcade / Go kart Park. I was refilling the coin machines. I had four bags, each bag had $500.00 dollars in quarter in them. Right before I set them down. I was carrying them up and over my shoulders. Well, this guys steps up behind me and sticks a nice round object in my back and says Hand up Drop the bags. I did exactly what he asked. Well two of the bags hit the floor, the other two hit is ankle. He was screaming like a banshee before I could turn around and see what had happened. I called an ambulance and the police. I probably would have avoided the police, yet he was screaming I had done it on purpose and he was going to press charges. I pressed Charges instead. The officer followed him to the hospital and took him into custody after his leg was put into a cast. Since I believed it to be a gun and the value was $2,000.00 it was a felony charge with a weapon. The DA asked what I truly wanted. I told him I wanted him not to press charges against me and not to take me to civil court. The DA got him to sign off, and I drop the charges.
Moral of the Story
It is when people are screwing around that people get hurt.
You could take the advise previously given which good advise, or you could consider asking them to stop. By explaining to them that the flinches might get a reaction out of you. Just a thought.
One of the things I tell all new students is not to tell anyone they are training. Their friends and family will know but not at work or at the bar, etc.,..., .
Good Luck
Rich