Answer:
Violating duty of fairness to Claudius
Step-by-step explanation:
Duty of fairness is defined as the process by which administrative decisions are made in in a fair manner so that the affected parties have an opportunity to put forward their views before the decision is made.
This results in a more inclusive decision making process.
In the given scenario Cleopatra decided to tell Tiberius about Claudius' offer and tells him he must beat the offer; Cleopatra doesn't tell Claudius about Tiberius because she thinks Tiberius is a much better fit for Caesar's lovely Grecian-style mansion.
This is unfair to Claudius as preferential treatment is being given to Tiberius.