Good Intention Is not Enough

You can see your friend painting the wall of his house.You can't see anybody help him.Seeing this,you are offering him a help and say "Can I help you?". He then say "Oh,really? That's most kind of you". And you then start helping him finishing painting the wall.While you and he are painting the wall,he gets a call from his wife and he has to leave to meet his wife because she wants him to take her to a drugstore.

So now he is leaving and only you now are painting the wall. When he is back and sees that you don't paint it as well as he does then he is unhappy and doesn't talk nice to you and you are so much offended and a vicious circle comes to happen