I can tell you how you should have told him to stop.

"Hey... I want to talk for a bit about the "Stay of trouble" remarks". Look, I know you have the best intentions and I appreciate your trying to be funny and also being protective of me. But it just isn't funny for me, and I also do not like that you are saying what you are saying in front of your staff. I believe it makes me look bad. Please do not do it again, OK?"

here he would say something

"It is all good. You know that I value your services. And I am sorry that I did not tell you that I did not like the "stay out of trouble" remark when it was first uttered but instead hoped for you to interpret my lack of laughing at it as a hint that you should stop. I won't expect you to read my mind again. You are a chiropractor, not a clairvoyant".

here he would say some more

"It is all good. We are friends. You are the best. And don't you worry, I AM a good girl now and stay out of trouble, with your blessing".