This is son hard isn't it? I don't want to give OW any more power than she already has and become controlling yet I want what's best for the children so as they can maintain some sort of relationship with their dad.

I think initially I will organise the visiting schedule and then maybe tackle the texting when they are with him if it continues.

Interestingly on Friday after he texted her and she text back he frowned at the answer. I know that look and it mean't 'what are you doing/saying your pushing the boundary now'. He then stayed extra time with his children so I think your right about her becoming increasingly needy!