According to The Book, do Atheists really have invisible horns on their heads?

Hey dear Starjumper.

It's your fault that I'm stuck here in R&S.

You did this to me.

We do have invisible horns, we toot them whenever we can.

When it says invisible, does that also mean we can't feel them? Because I do get splitting headaches sometimes but I've never been aware of any protrusions.

which book?

I don't recall reading anything about it in the god delusion...