Apples Photo App Won't Quit

Apples Photo App keeps opening and won't quit and cannot be shut down. Force Quit, etc., does not help. even typing this question, it pops up in front. when put behind, it pops forward and blocks the active window. The photos from my iPhone, two iPads, and this MacBook Pro all pop up and they do it at startup.

Since it cannot be deleted, HOW do I shut the thing off for ever/permanently?

It seems to me a lousy trick Apple is playing with 10.11.3