Don't make him MAD again!
Nobody wants to see that............
Just to make sure my post was clear, I shall expound on the meaning of each word:
"Don't"---Contraction for do not. Used here to intone that the action indicated by the sentence's verb should be avoided, or considered to be prohibited.
"Make"---Used here not to indicate the creation or formation of an object, but rather the causation of an action. In this case, do not influence, force, or otherwise cause the indicated poster to take the action or emotion indicated.
"Him"---3rd personal pronoun used to refer to the poster to whom you were replying.
"MAD"---Can be used to indicated a crazed or insane state of mind or an emotion of anger and/or rage. Used by some to indicate an excitement related to the NCAA Men's Basketball Championship. Used here to refer to the emotion of anger.
Please consider yourself prohibited from causing a state of anger in the poster to whom you replied.
"Again"---The poster to whom you referred has made posts that some consider to indicated anger in the past. Please do not be the cause of this happening again.
Thank you for your time and attention, and especially your cooperation on this matter.