Because I think I see more of his than I do of my own husband's 
My very unattractive and portly over-the-road neighbour seems to enjoy fannying about in his bedroom completely in the buff. His window is right opposite mine and I only need to be doing something like pulling my blinds up and it's like "Woah, and there's your nob AGAIN."
Other people in our terrace have noticed it too. DH and I have speculated that he might be a bit of an exhibitionist as it's not even like he's naked but trying not to be seen. He stands right in the window with his family jewels out on display most days. I had to pull my blind down yesterday and put my make-up on with no natural light just so that I could avoid getting my eyes assaulted by a stranger's cock.
How should I deal with it? I've thought about mentioning it to his wife, as in "I don't know if your husband realises, but we can see a lot more of him than he probably realises. You might want to close the curtains in your bedroom in future!" or I've thought about drawing a very unflattering picture of said neighbour in the buff and anonymously posting it to him. It would be captioned "THIS IS WHAT I SEE EVERY TIME I GLANCE OUT OF MY OWN WINDOW! STOP IT!" Or I could just ring the police and report him for indecent exposure. Last one seems harsh though.
I'm not being U, am I? It's not a one-oof, it's most days. And it's rank. :(