I'm coming to the conclusion that sometimes it's best for everyone, most of all the DCs concerned, that unless the RP is supportive, DCs are better off without contact with the NRP.
I know there is a risk of long-term psychological issues and I'm sure that it increases the chances of difficulties when they marry/become parents themselves, but I think it is unfair to subject them to the emotional conflict and turmoil of spending time with one parent when the other disapproves/objects.
If they choose to see the NRP when they are adults then great, but to be honest, if they've not had a relationship with that parent as a child, then they're not going to relate to them as a blood relative; it will be an adult relationship based on whether they get on as individuals.
Can anyone convince me otherwise? I'm very uncomfortable thinking this, but it seems the only logical conclusion based on my experience.