Sexual attraction between two Christian lovers is healthy as long as it is not allowed to overrule their desire to honor God in their lives. When it is allowed to overrule and reject the Word of God, their sexual attraction turns into lust, not love. Lust means wanting to have sex with someone you are not married to (Matthew 5:27-28).
Sin always lies to us. It always hides the truth from us. It says, for example, to unmarried couple, “Even if you two are not married today, you will soon be. So, enjoy each other’s body today so that you will be happy.”