The title pretty much sums it up – except to add, she didn’t do a very good job of it.
He keeps his hair short, but somehow she managed to gouge out large sections that were less than 1/4-inch long. He wound up going to a barber and getting everything trimmed to 3-day stubble length.
His mother and I have spent two days reassuring him that it doesn’t look that bad and will grow back in any case – then we go into another room to laugh.
The original “trim” was her idea. What some guys will do for their girlfriends!