Harassment - kids

Big fat leech giving me problem again.........
Last night came at 8.10pm while I'm not around, but my mum was, and demanded to bring the girls out. My mum told him it's late and can't bring the girls out as tomorrow they have to get up early and go to schoold.
He hurled and scolded vulgarities at my mum, worst he even clenched his fists displaying violence as if he wanted to hit her. If not for his father pushing him away, who know what he might do to my mum.
This just shows he lacks of respect for elders. It's really like my friends say any guy outside will be better than him.
Very self-centre and arrogant. He affirm my decision in divorce. I know for sure he won't be the guy I would want to spend the next half of my life with. One who's arrogant, self-centre, indecisive, show no remorse when done wrong, and worst disregard of others.
Can anyone be worse than that? Refused to give due maintenance, yet keep giving kids stress. I would say a very lousy father.