Advice needed. How to handle GP.

I had my annual check up today and my blood pressure is up there again. I was advised to see my GP and had an appointment made for friday. I'm not to worried as my blood pressure has always fluctuated. I do want to speak to him about exnh who, although he lives quite a distance from us is still his patient. How I know? He's been discussing us with the GP and telling my children all about it. Not acceptable to me. I need to straighten this out. I live in Europe and it is not possible to change GP's unless you move more than 10 km away from them. I think exnh needs to get another GP and I think the GP needs to tell him. Now, my GP is not the easiest man in the world and will not accept me telling him to do so. And I feel like yelling at him " why are you discussing us with a disorded person!!!' I know he will come back with a remark about me not being a doctor so I can't draw such a conclusion. I'm rattling my brains trying to come up with a solution. I don't know if he discussed anything medical, if so it would be easy. I don't even know if he talked about anything as assclown could be lying. How do I go about this? This needs to be resolved.