be in the worst possible taste

To be highly offensive or inappropriate (resulting from poor judgment or a lack of standards by the person who said or did such things). Some people thought that wearing such a bright outfit to a funeral was in the worst possible taste, but it was meant to be a tribute to my friend. Your use of those words was in the worst possible taste. I can't imagine something more offensive. You just met these very influential people—talking to them about politics and religion would be in the worst possible taste.

be in bad, the worst possible, etc. ˈtaste

be offensive and not at all appropriate: Most of his jokes were in very poor taste.