Forgive me if this sounds presumptuous, but even if you are not a religious person, speaking to a local pastor might be an option. Or perhaps there is a local divorce group to attend and share with.
Why do you think your son needs to know that your W is having sex or emotionally intimacy with someone else?
Or are you simply wanting to let him know that his mom is planning on leaving...?
And if so, why would you not consult with your W first as to how to go about discussing this with your s?
