How do tell your partner???

[zebraman]

I have asked a partner like that, "don't you trust me?" He says "what?" I say, "don't you trust me?" He says, "what do you mean?" I say, "well, you keep calling things in my primary coverage area so you must not trust me as an official."

He apologized and didn't do it anymore.

Like others have said, if the subtle remarks don't work then you can go to something more direct.