Truthfulness pays
There are always two sides to a coin. In any situation you can always tell a lie or revealing the truth. Most of the times being truthful paints you in a bad picture or puts in you delicate situation with respect to others. But being truthful helps you and also the other parties involved in the long term. For example, when you are truthful and have put your friend in a problem, after some time, when he becomes rational, your friend will be able to appreciate you for being truthful even though your were tough on him. Also psychologically being truthful helps you to be cool and calm because you are not doing anything against your inner heart i.e, conscience. So be truthful always. it pays.