Both my lady and I know many people who abide by this "logic" that it is ok to cheat and lie about it.
We just shake our heads ruefully. I guess we are of a different time.
In this day and age, when it is not socially required to be married why do people get married and then cheat? Don't get married but have multiple girl/boy friends if that is what you wish.
I seldom like to push my moral values on others and everyone will live their lives the way they wish. But to us:
Cheating on your spouse or committed domestic partner is wrong
Lying about cheating on your spouse or committed domestic partner is wrong
To us, there as just some things in life that are that simple.