It is natural for men to have six to twelve erections during sleep and frequently waken in the morning with an erection. These may or may not be associated with sexual dreams or wet dreams.
Men often enjoy the feeling of waking with an erection, and some will masturbate first thing in the morning. Early in a marriage, most men are shy about letting their wives see them with an erection at night or in the morning. These men usually feel a great sense of relief when their wives discover their nocturnal erections, and then let their husbands know that they understand and are OK with it. Some wives take it a step further, and want to play with or use their husbands’ nocturnal erections.