What does "DUH" mean in this statement?

[I'm still learning]

The statement: -

Okay, that makes sense. I can tell in all honesty if someone posted nude pictures on my wall or whatever else, I would not know how to get off! Duhhhhhhh!

Please let me know what the word DUH means at the end. What's the speaker trying to say?? He wouldn't know how to remove the nude pictures from his wall???

 

[bertietheblue]

What an idiot [you are/I am]!

 

[I'm still learning]

What an idiot [you are/I am]!

So the speaker's actually saying that I'm an IDIOT!!! WTH???

 

[bertietheblue]

So the speaker's actually saying that I'm an IDIOT!!! WTH??? I wouldn't read that much into it - he's simply being light-hearted.

Bertie

 

[duiter]

see this link

duh - definition of duh, by Macmillan Dictionary: Free English Dictionary Online and Thesaurus.

 

[Raymott]

I can tell in all honesty if someone posted nude pictures on my wall or whatever else, I would not know how to get off! Duhhhhhhh!

See here for the meaning you want.
Urban Dictionary: get off