Song of Songs tells us in numerous passages not to "stir up or awaken love until it pleases" (2:7, 3:5, etc.).
The orthodox, uncontroversial interpretation of this language is that it instructs men and women not to relate in ways that arouse or encourage sexual desire or a high, unique level of intimacy until it is appropriate (i.e., within the context of marriage illustrated in the book).
Numerous scholars have suggested that beyond the clear sexual implications of this passage, there is a broader relational application that we are not to "defraud" one another in areas of sexuality and relationships by implying a marital level of commitment by our words and actions that does not exist.
Again, Romans 13 talks about doing no wrong to our neighbors and then names sexual sin as just such a wrong.
Call this the positive corollary to the sexual sin principle.
Scripture treats marriage as a unique and exclusive relationship, not just in its status, but in the means of relating within that status.
Similarly, 1 Thessalonians 4:1-8 warns us that we are to abstain from sexual immorality and to use our bodies in holiness and honor rather than lust, and that we should not "transgress or wrong" one another in these matters.
Other translations render that word "wrong" as "defraud" (see the old RSV, among others).