They all shunned him because he was a lecherous man always looking for an oppurtunity to cheat others.

Cunning : having or showing skill in achieving one's ends by deceit or evasion.
Deceptive : giving an appearance or impression different from the true one; misleading.
Lustful : having or showing strong feelings of sexual desire.
Dishonest : behaving or prone to behave in an untrustworthy, deceitful, or insincere way.
Lecherous : having or showing excessive or offensive sexual desire.

Synonym of Lecherous is Lustful