Think I have to tell the police an/or social services TW abusive father

Why not the pants thing? That's awful too.

I'm so sorry. Please. You have to say something. Especially now there are grandchildren involved. He could be doing the same to them.

Please encourage therapy, they need to work through these emotions in a safe environment. They acknowledge his behaviours, but still have that unhealthy bond/guilt with him. Which is completely understandable and common. As mum, who just heard some really upsetting news about your precious children, and struggling with not knowing fir so long, you may want to consider leading by example and also going to therapy.

Yes you do. I’m sorry your kids have experienced this.

I have been through similar with an abusive family member. I think you need to get support in your next steps. This will cause a huge fallout but nevertheless I personally believe they should report it so they can finally face up to the reality of their father.

Do not underestimate the level of support you will need as a family and do not underestimate how this will mean the end of the relationship with that part of the family which is a good thing ultimately but will hurt like hell too.

You have two adults who know their dad's behaviour is not acceptable. Have a conversation where you explain that you are going to report it because other children are attending risk. Explain that you would have done anything to stop them having to go through that, so the guilt of not saying anything and potentially putting another child, like the grandkids, in harms way is too much of a risk. I would also encourage therapy for both, which can be done through their GP. Also, why does you son still see dad? Does your daughter? I would be encouraging them to go no contact, therapy will help them work through that guilt associated with an abusive parent. I really feel for you and your kids, that is awful for you all. I am so sorry.

You need to tell your children that you can't keep this to yourself because you need to try to protect the other children. You need to report it to the police and encourage your children to give statements. It will be the end of their relationship with their father so they need to be prepared for that.

Please report it. I'm 42 and currently battling huge mental health issues as a result of the abuse I suffered at the hands of a family member when I was about the same age as your children were, but also the way in which my parents dealt with it (ie they called me a liar and actively sought to discredit me) when I disclosed at school and it was reported to police.
Their experiences may be historic but there's a chance other children are in danger now, please report it and support your children in working through it.x

I think you should contact the NSPCC for advice, both on how to convince them to report and what to do about him being around other children. Your son is an adult and your DD is almost an adult. It’s not you who will have to go through the trauma of reliving those experiences and speaking to police officers; it’s them. And you have no right to force either of them to do it against their will. Find out what their reasoning is for not wanting to report. Is it fear? Of repercussions? Of not being believed? Of not wanting him to get into trouble? Or fear of what they’d have to do as far as potentially attending court etc? And then you know what you’re working with in terms of how to convince them that it’s the right thing to do. And both of them need trauma counselling.

What your daughter said especially, not the pants thing but the other stuff, is very serious. You need to report that

The wife's grandchildren are in horrible danger. You know that it's possible. You should tell the police and they will investigate.

Yes you must report... Your children have the option to not disclose their experience to the authorities but if you don't report and other children suffer, you will have to live with the fact that you did nothing and could have prevented abuse

Please contact the police.

You need to report him to protect others from him, what a vile piece of shit he is, I can understand your children not wanting you to but this is something you absolutely must do

How old are your teenagers now and what prompted them to suddenly tell you?

Yes, a violent sexual abuser should be reported but if your kids don't want you to, then I'm guessing they'd be unlikely to back up what you say to the police?

Awful awful situation.