Please stop pissing about talking on the phone and having little chats about life, BB, the DC here and there.
He saw the DC, then called later to chat to you about it? WHY?, he is garnering support from you again! Cut off that lifeline.
he is trying to smooth everything over, has faked mental illness, has harmed himself to fake smashing up her flat, wheedled out of being honest with his DC, threatened to never see them again unless you did what he was demanding.... and is now trying to extract marks out of 10 for love for him from the children whose life he has turned upside down.
He is touching you and stroking you, trying to keep you sweet too, to make himself feel better. What an utter skunk.
Tell the DC that no matter what they want to ask, no matter what they think about anything, if you can help them, or explain anything to please come and talk to you, that you will always be there for them wherever and whenever they need you. You are now a team and all there to help each other.