For a start.. if you said hes always smoked weed.. i think your answer is right in front of you. Weed makes you so paranoid its unreal not to everyone, but thats the main side effect.
Then again cocaine always makes you paranoid… especially when your on it. When hes come home inspecting everything is he on coke? Because it could be the coke. Ive heard people do strange things on it.
Then the other one is.. he could of been up to no good himself and he takes it out on you. Ill be honest cocaine does make some people cheat. Just like people blame alcohol on cheating..
Has he quit it then?