He threatened to leave because you clean up after your brother? That is really odd.

Are you sure you really like him? Because I don't think *I* could live with that kind of instability.

Maybe you should tell him that you are unwilling to tolerate that kind of threatening, and the next time he does it you are letting him go. (But only say it if you mean it.)

Otherwise, I guess you will have to learn how to live with this.

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