you have been franks best friend for years, you know Frank was abused heavily as a kid and he has severe childhood trauma and the way he copes with that is regression. There isn’t anyone he feels as safe around then with you and you agreed to be his carer when he feels the need to regress and help cope.

Frank calls u to come to his and by the time your over he’s having a panic attack it’s usually something which happens before he regresses and he needs comfort so he can regress