To criticize one harshly and undeservedly, often due to frustration. I know you're stressed about the wedding, but why are you doing a dump on me? I didn't intentionally bring the wrong box of place cards!
do a dump on someone/something
and dump all over someone/something and dump on someone/something
tv. to criticize someone or something; to destroy someone or something. (From take a dump, to defecate.) That rotten jerk really did a dump on my car. Look at that fender! She did a dump all over my report. Why do I bother.