what else other than a stiff neck?

A man came to visit his grandparents, and he noticed his grandfather
sitting on the porch, in the rocking chair, wearing only a shirt,with
nothing on from the waist down. Grandpa, what are you doing? Your
weenie is out in the wind for everyone to see!" he exclaimed.

The old man looked off in the distance without answering. Grandpa, what are you doing sitting out here with nothing on below the waist?" he asked again.

The old man slowly looked at him and said, "Well...last week I sat out here with no shirt on, and I got a stiff neck. This is your grandma's idea."