The chief

An African chief went to the doctor to find out why he couldn't make babies ... the doctor checked him over thoroughly and said 'I think I know why.'

Next day he’s all dressed up in top hat and tail coat with a silver topped walking cane ...his wife saw him and asked 'why are you all dressed up like that?'

He says 'well the doctor said

Spoiler:

I was impotent so I’m gonna look impotent'