Thank you for your question
My name is Clare
I shall do my best to help you but I need some further information first
In what way do you think seeing her will put your son at physical or emotional risk (bearing in mind he is not aware of the history)?
I do understand all of that but I have to be honest there is a limit to the control that you have over the contact that your ex has with the child.
For the avoidance of doubt there is no basis whatsoever on which you can ask for DNA testing of "his" older children - so please on no account even mention it.
At this stage your strongest argument is that it is too early after the separation for anyone else to be involved in contact at all.
It would be reasonable to establish a regular pattern of contact so that your ex sees the child for a few hours once a week with a review after three months, but at that stage if he is still with her I am afraid that it is unlikely that you will be able to successfully exclude her and her children from future contact.
The starting point is for you to discuss matters with your ex using Family mediation to agree a Parenting Plan
I am sorry - I am aware that this is not the news that you are looking for but sadly it is a realistic assessment of the position
Please ask if you need further details
i agree - much much too soon