Comment: What exactly is the plural of penis?

(See in situ)

In reply to comment: I had to look it up, figured (see in situ)

What exactly is the plural of penis?

What exactly is the plural of penis? I would say penises, but it seems too simple and obvious. Is it penis, like deer, or maybe peni, like fungi?

— Sissy, Emerald Isle, NC

lol..