You know the routine.
Their relationship didnt work out, the formerly 'happy couple' split up & dad is devastated.
He dotes on his ex's whims in hopes of not having his kids kept from him.
This goes on for awhile and the ex enjoys a life that often times includes a new boyfriend doting on her as well as the ex trying to stay in her 'good books' so he isnt pushed out of the picture entirely.
Then dad gets a new girlfriend.
He is placed on the 'naughty list' by his ex, often times the oldest child becomes his mother's spy and informant on what is going on with the new girlfriend.
The ex becomes jealous.
She begins to withhold access claiming 'they're busy' this day or that day..
Finally she just cuts access off altogether & informs Dad that "your access wont be re-instated until you get a court order".
Dad's children suffer, grieve and blame themselves.. they wonder why their mom is now telling them they arent safe with their dad, or that he is a bad parent.
The children suffer, the bio mom feels she's won a battle, and the children continue to suffer.