There are a few general ways that we cause harm with our sexuality. The most egregious is through coercion: rape, making sex the cost of a promotion or job retention, intimidation, blackmail, and bullying. There is nothing wholesome in these actions.
At a more intimate level, the betrayal of trust is another action that causes harm. If you are acting in ways that you need to hide, that you wouldn’t want your partner to see, then you are harming yourself and your (or someone else’s) partner. Flirting with someone other than your partner, in your partner’s presence (or even not), is hurtful. Lying to your partner – don’t do it! Better to restrain yourself from doing any actions you might have to lie about.
Probably the most common way that harm is caused with sexuality is by leading someone on. This happens when one person is interested and the other is not, but pretends to be. The pretender gives an insincere commitment, or none at all, and takes advantage of the (wishful) partner’s hopes and desires. Twice I have encountered men who cohabited with women whom they didn’t acknowledge publicly. Friends and acquaintances discovered (during the breakup) that there had been a hidden partner for years. Meanwhile, the guys had behaved as if they were single. How much dishonesty is required for that situation to develop? How could such a person be considered trustworthy? How can the hidden partner recover from such humiliation?
There is an infinite number of ways we can harm each other with our sexual energy. Using care, we can prevent all of them. We try to avoid harming others and also avoid being harmed ourselves. If we do harm someone else, we stop as soon as we realize it, apologize, and resolve not to do anything like it in the future. If we have been hurt, we try to work out how we allowed or invited the hurt and seek ways to avoid similar situations in the future.
The great illusion
“…the interesting thing for us to note is how sex — like everything else — is a purely impersonal force. We tend to think of it in intensely personal terms, but in actual fact it is a force that just flows through us and uses our most wonderful and inspiring emotions for its own ends, which are totally concerned with the continuance of the race as a whole. The idea that it is just a private and wonderful thing between you and me is merely a part of our general illusion. Altogether, it is a prolific breeder of illusions. It can lead a man to think he has found the most wonderful woman in the whole world while everybody else is thinking, “What on earth can he possibly see in her?” “(Maurice Walshe, Buddhism and Sex.)
Key to seeing this great illusion is knowing when our mind is colored by lust and when it isn’t. In the example above, the man doesn’t realize his perceptions are being distorted by sexual desire, but the observers, unaffected by lust, see more clearly. If we recognize that our mind is affected by lust, we can put the brakes on, move away from temptation, take a deep breath, or do whatever it takes to remember that danger is near and we need to guard our actions.
“… a bhikkhu [practitioner] understands mind affected by lust as mind affected by lust, and mind unaffected by lust as mind unaffected by lust.” (MN10, Nanamoli/Bodhi)