There is a somewhat famous statement in Christian circles that “it is better to marry than to burn.” That’s a poetic way to talk about passionate, erotic desire for someone else. In itself, there’s nothing wrong with passion, but there is only one safe direction for sexual desires: your spouse.
Remember King David. He was already married, but then he saw Bathsheba, and in many ways his life was undone. It was unlawful desire. It destroyed him and many lives around him.
In Proverbs 6 Solomon shares wisdom with his son, starting with exhortations to learn from the ant about not being lazy, and then moving to reminders about mom and dad’s teaching on purity. There’s a lot of warning about the “strange” woman in Proverbs, and there are a couple verses about obvious danger.
Can a man carry fire next to his chest
and his clothes not be burned?
Or can one walk on hot coals
and his feet not be scorched?
This is a different kind of burning, and the consequences are unavoidable. The questions don’t reveal information, they are a memorable reminder. How far can you carry a candle around under your hoodie? What number of jumping jacks can you do barefoot in a bonfire? It’s impossible to avoid the pain, and Solomon presses the image into adultery.
So is he who goes in to his neighbor's wife;
none who touches her will go unpunished.
It is good for a man to touch his wife, it’s not good for a man to touch another man’s wife, or any woman who’s not his wife. It’s good to love your wife, it’s not good to lust for anyone who isn’t (Matthew 5:28).
Where are your passions? Are you guarding your heart? Out of it proceed the issues of love.