DEAR MISS MANNERS: I can see in my neighbors' bathroom window. Should you tell them?
GENTLE READER: No, Miss Manners demurs. But you might, depending upon the circumstances.
Were you standing in the bushes with your hands on the windowsill? Does your bedroom look into the bathroom in question? Or did you make eye contact as you walked down the street?
In the last case, Miss Manners recommends a cheerful wave. Failing that, you should either close your own blinds, or work into a future conversation that you hope your neighbors do not find the closeness of the houses --and the resulting lack of privacy -- disconcerting.