If the uninhibited neighbours can be seen from the kitchen then likely they can see into the kitchen so will probably know they are on display! That being a strong possibility there does seem to be an insensitivity to others . I am no prude, and human bodies, nakedness are fab in the right place /right time etc but really it would spoil my fruit and yogurt to see a stranger scratching his bollocks so early in the day! I would call round or drop a note in saying you are not sue if they are aware that the local residents are not prissy but prefer not to have a cabaret at breakfast and perhaps blinds , shutters or even frosted glass would stop the neighbours being distracted at breakfast!
