To repeat - The reason is that where the sin is public suddenly we cannot assume that the person is in a state of grace, without information to the contrary.
Where is the PROOF that a sin is being committed? Without such PROOF, you are condemning when a person MIGHT be free of sin.
PaulAndrew83;4494450:
In the case of people living together, it is improper and generally people living together these days are assumed (if they are a couple) to be engaging in sexual acts.
Again, you are ASSUMING that are performing sinful sexual acts when that MAY NOT be the case.