For a joke, husband just reflected sunlight into my eyes from his watch. I asked him to stop singing a very repetitive and annoying song (repested with whistling, humming and singing for the last 10 minutes). His response was to shine the light from a perfect sun - no clouds, fully round, very bright sun - into my face.
Well, i lost it. I had to explain why it was dangerous. He replied that people had been doing it for 1000s of years. I just had no sense of humour.
So depressed that I am married to such a stupid arse.