Advice on my scenario pt. 20-Shock Therapy

[OrangeK]

I really try my best not to call her parenting into question. But Every time I've gotten my son after she's had him for a few days his behavior is atrocious. I don't know if she's neglecting him or just letting him dictate when and how he does things and not setting discipline or what. all I know is that every time I get him after she's had him he is overtired, obstinate, aggressive and argumentative. after I've had him for a day or two he goes back to normal. I hate Split parenting.