Not to the other person, but to God as you understand God. And God starts with the heart, in this case. In the old testement we get the law. The lie becomes the truth when one fools himself that he is in love, when in fact he is lustful. Lust is not only carnal knowledge, it is also flattery.
Flattery occurs also in marriage.
It is no less a sin there. True respect only occurs with one who puts God before anyone. You have to ask someone else this one. I don't know. I know some of these guys in the Bible had many wives.