Unfortunately, I made that mistake.
My ex didn't help with the children, he worked long hours.
I left the family home, left 2 of my children behind with him. Aged 8 and 5.
Took the toddler with me and I was also pregnant.
I was overwhelmed with his behaviour towards me, not helping with anything, if he didn't agree with anything I said, he would blank me and give me the silent treatment and just carry on with his own life. He was also financially abusive.
My ex the slime ball carried on working, would drop the children to school, come back at pick-up time and drop them at his relatives and go back to work.
I went back 2 weeks later and he wouldn't let me back in the house, because he had changed the locks, he wouldn't hand the children over either.
He called the police and according to the law, I had left the family home and left the children behind so I couldn't return if my ex didn't want me back.
My ex was a nasty, evil, controlling abuser. He refused to talk to me. For someone who paid no interest to the family and spent no time with his children, he suddenly just took the children from me. It was about control.
It took me 6 months to get the children back through the courts. This was 10 years ago and he has no contact with them anymore.
Unfortunately it was an expensive lesson to learn.
I was so naive, thinking our family meant something to him. He didn't care.