What is when a guy says sweet dreams?

When a guy says "sweet dreams" to someone, it is typically a way of sharing their good wishes for them to have a peaceful and pleasant night's sleep. It is commonly used by romantic partners or close friends as a way of expressing their care and concern for the person's well-being. Saying "sweet dreams" can also be a way of expressing affection and love, especially in the context of a romantic relationship. Overall, this phrase is a common and simple way of conveying positive intentions and well wishes to someone before they go to bed.