This precept is often stated as "A follower of the Way does not engage in *sexual* misconduct" and because of that it generates a lot of interest. I'm guessing that is because a lot of people have really definite ideas about what sexual misconduct is, or they are struggling with their own definition of the boundaries of proper sexual behavior in their own lives.
I think probably most of that rumination properly belongs to this precept, but my application of this precept is much more broad. *Sensual* misconduct is much closer to the mark. I think most sexual misconduct arises from an abuse of the senses. Most people get focused on sex because of the sensations that arise from sexual behavior. However, that idiot blaring the loud music at 3 am in the apartment next door is also engaging in sensual misconduct, as is someone who habitually overeats.
It is easy to miss the point here by focusing too much on the term misconduct, as if this were a punitive declaration. Misconduct in this context just points to doing something unwisely. A person chanting sutras who so enjoys the tonality of their own voice that they distract and disturb those chanting with them is engaging in sensual misconduct. It's not all about frankly violent or antisocial misbehavior.
The problem here is grasping at sensual experience as if there is something there within that experience which you desperately lack. Again, you might be seeing a pattern to my approach in these essays, it this the projection of your focus outward to some external thing in an effort to make up for some feeling of lack you experience within yourself. That feeling of lack is real, it is what Buddhist teachings address in the Noble Truths, but you lead yourself astray when you buy into the notion that there is something out there, separate from you, that can somehow solve that problem. This grasping at an external solution for the persistent dissatisfaction you are experiencing can cause people to bring rise to harm, the extreme case would be rape, and that is what this precept reminds us of.
In the movie "Spinal Tap" there is a famous scene in which the guitarist shows off his amplifier. He calls attention to the panel around the volume knob, which often has markings on it from one to ten. His panel has eleven as the highest number. It is a joke, and a really clever one, because it elucidates this very grasping at extremes. Of course, painting a different number on the panel of the amp doesn't make it any louder when turned all the way up, but ten wasn't enough for this guitarist. He had to have eleven.
Customizing the front of an amplifier isn't misconduct, at least not in my book, but the thing at which he was grasping, needing his guitar to be just a little louder in order to achieve something, is the same kind of desire that gives rise to the conduct addressed by this precept. A love affair that violates a promise of fidelity, engaging in sex with someone unable to freely give their consent because of age, their position as an employee or some other subordinate context, or of course forcing someone to have sex against their will are all actions that arise from the notion that some sensual experience is worth causing harm to another.
It isn't. Not only is it wrong, but there's actually no solution there. There is a way to address this persistent dissatisfaction in our lives, but it can't be done by hurting someone else, it can't be done by getting something somewhere. We all know this before we jump to the conclusion that our senses really can satisfy us, the knowledge actually precedes our mental conception of some sensual experience as a solution, so a follower of the Way, that is, one who does not indulge these concepts, does not engage in sensual misconduct.
Next - A follower of the Way does not speak deceptively.