At 2:35 of this video, Sheldon Cooper says
For the record I have genitals. They are ...
How can a person have more than one genital? Is it alright to use whatever grammatical number in casual speech?
As a Japanese who doesn't have the concept of grammatical number, I find it fascinating that a native English speaker can confuse the number and count his genital as not one.
Are there other reasons behind that?