Am I wrong?

My 14 year son will be spending time with his half brother (19 years old) this upcoming holiday season when he comes to visit their dad. I am worried sick because this 19 year old has learned to fly planes and says he has 300 flying hours in and wants to take my 14 year old. I said no cause I do not want my son going with someone that young and not much experience. He kept bugging my son this evening when I said no several times and I started to cry and I called their dad. It would be different if he was older and had many years experience but I am sick thinking about my son going flying with him. His dad told his older brother to quit asking. I felt like I was being disrespected because he could not accept what I said. Am I wrong?