I have thought of situations and how to solve them.
somebody has borrowed your favourite book and you have no any intentions of loaning it to them because the last time you gave them something they never returned.
Just tell them that the book is at home and you will bring it the next day, for the next one week keep forgetting . They will get the hint but won't hate you for it because the only one to fault here is your bad memory.
Your girlfriend has caught you pants down with the girl next door.
pretend nothing has happened and do not follow her even when she seethingly walks out screaming its over and do not even try to communicate or say sorry.
Reason; She will now start to wonder if the girl next door has taken over her place and come running asking if anything is wrong. To which you must have a ready answer.
You have lost somebody's expensive book and you have no money to replace it.
Tell them you are going to replace it as soon as possible when a cheque you have been waiting for is cleared. Buy time but keep promising that way they will realize your good intentions to replace it.
To end a fling
Simple, try taking it to the next level.