hitting the nail too squarely on the head
Expressing oneself too directly, too plainly, insensitively.
I once considered buying a birthday card for my dad that made fun of his age. My dad was in his late 60's. It portrayed a man in a car looking in a rear-view mirror with a panicked expression, and seeing the Grim Reaper. The message printed on the mirror was, "Objects shown in mirror may be closer than they appear." I thought it was hilarious, but I thought it was "hitting the nail too squarely on the head." It's implication was too direct.