Definitions

Adultery

(also called philandery) is a form of extramarital sex. It is sexual infidelity to one's spouse. It originally referred only to sex between a woman who was married and a person other than her spouse. Even in cases of separation from one's spouse, an extramarital affair is still considered adultery.

Scandal (sex scandal):
A sex scandal is a scandal involving allegations or information about possibly-
immoral sexual activities being made public. Sex scandals are often associated with movie stars, politicians, famous athletes or others in the public eye, and become scandals largely because of the prominence of the person involved, perceptions of hypocrisy on their part, or the non-normative nature of their sexuality. A scandal may be based on reality, the product of false allegations, or a mixture of both.

Truth: 

Truth is always an absolute defense against a defamation suit in the United States.

Lie:

A lie (also called prevarication, falsehood) is a type of deception in the form of an untruthful statement, especially with the intention to deceive others.To lie is to state something with disregard to the truth with the intention that people will accept the statement as truth.
A liar is a person who is lying, who has previously lied,
or who tends by nature to lie repeatedly - even when not necessary. 

Lust:

Lust is an emotional force that is directly associated with the
thinking or fantasizing about one's desire, usually in a sexual way.
 noun
1. intense sexual desire or appetite.
2. uncontrolled or illicit sexual desire or appetite; lecherousness

Just in case you hadn't looked these up lately-Thank you wikipedia for your clarity!

(I'm open to suggestions for more definitions...I'm sure wikipedia has them)