You should always flush the toilet after you use it.
Jack was at his friend's house when he realizes he has to use the bathroom.
Jack wants to poop.
Jack poops in his friend's toilet and makes sure that everything goes down the drain.
Jack poops in his friend's toilet but doesn't remember to flush it.
Jack and his friend are able to enjoy the rest of their visit.
Jack's friend is disgusted and tells him to get out of his house.