I think you're taking it WAY to seriously. All he was doing was gesturing towards the correct position as to what you should be doing, especially so because he did it in front of an entire gym. It's like in weight training when your instructor will push in on your back and down on your shoulders to gesture you towards how you should be lifting the weights.

I could get feeling uncomfortable if he grabbed and rubbed your *** with his hands, but a slight downwards gesture with his foot is nothing.

Believe me, he'd never try to do anything like that because that could create a reputation and end his career.

You're worrying way too much lol.

I was in karate for 5 years, which required perfect stances that often needed tweaking. My sensei or sempei's would sometimes move my arms or legs to the correct position if I needed a little nudge. They are there to help you, and sometimes moving you is the best way to demonstrate what needs to be done IMO

Touching your A** is not appropriate

If you don't feel like that is apropate tell him. if he does it again get rid of him

Ok I am not a child nor a teenager. i am actually 20. Today i was working with my personal trainer at the gym and then I had to do press ups then he hit my *** with his foot and he said you have to move your bottom down. i am pretty sure he did not mean anything as we were training in front of everyone but I did not feel comfortable? is this normal?