It sounds like he has developed a dislike for you or lost respect for you in some ways and he is demonstrating that to others at your expense which is not very professional at all. I would seriously consider quitting a jerk like this unless you can change this around to the point that he does not do this anymore. To me if I don't like you or don't like something you did I am going to let you know about it but I am not going to belittle you in front of others and make you the butt of jokes and my ridicule on a continuing basis in front of the class. That's not only unprofessional but disruptive to others and their training.

A good coach or good instructor will give you the full benefit of his training, knowledge, and experience especially if you are paying them in spite of their personal feelings about you and something in a lot of cases. If this idiot is not willing to do that then I certainly would not continue paying him and probably continue training there with him.

Sounds like he is upset that you don't want to fight anymore and is taking it out on you like a little kid. You could confront him about it or just go to another Muay Thai gym, but let him know why you left. Just maybe he might learn a lesson next time he considers doing this to someone else. If there isn't another Muay Thai gym in your area then consider taking up another art.

The bottom line is that there MUST be mutual trust and respect between an instructor and their student, irrespective of personal feelings. Otherwise, as seems to be the case here, it is not worth your time. His behaviour is clearly out of line, and completely inappropriate for someone in his position.

First thing is leave. Don't bother confronting him. Just leave. As it would be such a shame to waste all that time you have been learning, just find another class. There are plenty of instructors out there, and thankfully the kind of attitude you seem to have encountered is in the minority. You deserve to be treated with respect.

Quit.

Find a different club. He has no right to treat you like that.

I'm 17 years old and my Muay Thai instructor hate me I think he always makes fun of me in every lesson in front of little kids so the whole class starts laughing at me and when he is trying to demonstrate a combo he goes really hard almost as if he is giving his while power in a kick out a punch there are other 17 year olds and he doesn't hit them as hard also the other day when he was clinching me he told me he has no respect for me and the me on the ground, I always take it as a home and make silly little jokes but I don't understand why he's doing this to me, I've been going their for three years and he starting to do all this a few months back, when I had my first fight he was OK with me but after I stopped fighting all this happens he treats little kids with more respect than me and I don't know why, what should I do.