I had this a few years ago, block of 8 flats and I do 3 of them,2 first floor and 1 ground floor. A new tenant in a ground floor one below the one one first floor that I clean came out and said you are making my windows dirty, will you clean them please? I said well that means you are getting them done free, do you not want me to add you to the list? She said no I like washing windows, so I said well in that case what is the problem?
Each time I went the curtains were permanently shut and the windows were filthy,if she was in I would rinse the splashes off, if she wasn’t I just left them.