This set of posts comes from Pastor Mark Driscoll and his wife Grace. The sermon series The Peasant Princess brought up dozens of questions that they felt they should respond to. The result is this blog series: Christian Sex: Frank Answers to Honest Questions.
Answer: Men who have erotic dreams must first be sure that they are not spending their days filling their minds with images that rattle around their imagination as they dream at night. They should pray before they sleep each night that God would protect them from the enemy inside of them (their flesh) and the enemy outside of them (the devil). But if a man should have a wet dream after taking precautions to not lust, there is little he can do to prevent this from happening. For some men, a wet dream is simply the body’s way of relieving itself and may be little more than a natural biological function. If a man has a wet dream about his wife he is not in sin but likely should have more sex with her or should explain this to her in advance and wake her up at night when needed to be intimate with her.