Preteen means 11 or 12. Definitely too early to start this but we live sadly in a sexually charged society. The first thing of course is to sit down with them, probably individually, not together, and ask some questions.
A man (dad or trusted relative/teacher) needs to sit down with the boy and a woman (mom or again trusted relative/teacher) with the girl. First, where did they get the idea. If the kids watch alot of tv, they may have gotten the idea from there, in which case, it's really quite normal to emulate what is seen on tv.It could be that they got the idea or information from kids at school.
Ghly unlikely but there could be some kind of secret sex thing going on at the middle school that all parents would need to know about. Of course, keeping cool about the situation not to scare the kids is best too. If the parents want to find out what's going on - first they have to gain the trust of the kids to let them explain it.
If the parent does not feel comfortable asking these questions, then I would definitely consider some type of counseling. The other thing I'm thinking of is some kind of sexual abuse against one of the kids.So in this scenario I can think of two things: the one that is being abused is trying it on someone else or that the one being abused is trying to pass the abuse on to another person. This would basically be the beginning of a cycle of abuse.
So for these reasons, I think the parents have to get at the root cause. If it is just playful experimentation, then that can be dealt with. But if there is something more going on, then that needs to be dealt with an entirely different way and may require more than just the parents to be involved (school personnel, authorities, etc. ).
Agree that in order to make a decision, you need to ask questions. I would sit down with each of them individually. I would ask them to be honest and assure them that to be curious is natural, but inappropriate with each other.
Understanding that they are step - siblings and have no biological ties to each other. Another factor to consider is how long they have been siblings. If you through to 14 year old kids together in a house, that could be asking for trouble.
They didn't grow up to be siblings, as far as they are concerned, this is a stranger or similar to a classmate. If it was a one time incident, I would explain that because they are siblings now, that have to treat each other this way. I would then pay very close attention to how they react and respond to each other.
If it happened more repeatedly enlist the help of a therapist. As this is a very tender age, and the wrong response to this very sensitive subject could steer them in a direction you'd prefer they avoid. If after speaking with them, it was more one sided or there were aggressive actions, you need to get professional help immediately.
You must address this and prevent any further actions that could lead to harmful and unhealthy conditions for either of them. Or lock them each in their own rooms until the hormones wear off.
To much missing info'. Do the kids know that she knows? Was it a girl teaching a boy how to kiss?
Was she explaining what feels good? Is he trying to find out what to do because he likes a girl in school? Realize if it's between them what she says could scar them for life or drive them deeper into secrecy.
Maybe it is innocent. But just be glad their not really related and there are certainthings that will just run their course.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.