Wake me @6

After a very long , angry and tiring argument, Mr. and Mrs. Williams went to bed saying that they will not talk to each other now. Mr. Williams want to wake up early in the morning, so he left a note on his wife’s side bedtable by writing “Wake me at 6 am.”
When Mr. Williams awoke late at 11 am in the morning he quickly move out of bed to see a note on his bed’s side table:
“It’s 6 am , you bum! Get out of bed!”