what does this sign mean?

[posts from hell]

This is the sign I know for stubborn tooo.

But it is not what she described at all.

Oh out front of forehead, gullible?

 

[Bottesini]

Oh out front of forehead, gullible?

I don't even know the sign for "gullible" and can't find it in my favorite dictionary, so I must defer to you.