One possible reason could be that the boy misbehaved towards the girl. For example, if he bullied her at school or in the neighborhood, the mother might feel the need to discipline him. Another reason could be that the boy did something that violated the family's rules while in their home, like breaking a precious item or being disrespectful.
One possible reason could be that the boy did something really disrespectful towards the girlfriend or her family. For example, he might have been rude to the mother directly. Another reason could be that he got the girlfriend into some serious trouble, like getting her involved in dangerous or unethical behavior.
One reason could be for fun. Maybe the mother just wanted to have a laugh and see how cute her son would look in girl's clothes. For example, during a family photo shoot or a special family event like a themed party at home.
One reason could be to show authority. A friend's mother might feel the need to discipline another child if they are causing trouble in her home. Another reason could be a lack of proper communication. Maybe she didn't know how else to get the child to stop misbehaving. For example, if the kids were being too rowdy and not listening to her requests.
Such stories are not very common. In most cultures, spanking is considered inappropriate behavior towards adults or near - adults like a son's girlfriend. If it does happen, one reason could be that the mother strongly disapproves of their relationship and is acting out of extreme frustration or a sense of over - protectiveness of her son.
One possible reason could be that the child broke a very important rule, like cheating on a test in the case of a teacher, or lying repeatedly to the mother. However, this still doesn't justify spanking.
In some stories, it might be due to the strict parenting beliefs of the time. Parents or caregivers might have thought spanking was a way to correct misbehavior. For a diapered boy, it could be that he was at an age where he was not fully toilet - trained and still in that stage of being disciplined while also being taken care of in terms of diapering.
One reason could be a sense of guilt. If the boy has done something really wrong and he doesn't know how else to make amends, in a very strange way, he might think that asking for spanking is a form of self - punishment. For example, if he accidentally broke something very precious to the family and feels extremely remorseful.
The boy might feel ashamed. Spanking is a form of public humiliation in a way, especially when it's done by someone other than his own parents. He may avoid the girl and her family altogether to escape the memory of the incident.
One possible reason could be that he is seeking attention. Maybe he feels ignored in his family or among his peers, and he thinks this rather extreme behavior of asking to be spanked might draw people's focus to him. Another reason could be related to some form of self - punishment. He might have done something wrong that he feels very guilty about, and in his mind, being spanked is a way to atone for his misdeeds.
Sometimes it could be a practical joke or a bet within a group. For instance, in a youth club, some friends might dare a boy to be a girl for a day or for a particular event as part of a silly bet or just for fun, which can be seen as a form of being 'forced' in a light - hearted way.