this happened to me last week, customer was out back garden, he seen me and ladders through window when i started, i seen him looking. he waited 10 minutes to come and tell me not to clean them as they are moving on, i said you could have said, he just looked bemused after he seen me cleaning them. ok i said, then i started to get ped off because he could have told me. so i just soaped up the applicator and just give his bottom windows a second soaping but i forgot to wipe off with squeegy. made me feel better. i passed later and they need cleaning now/ well we are only window cleaners. i will never clean first clean without getting paid. i just say ill call back and clean them when they can pay.