An ASS.. But its your kids who are suffering at his being and ASS.. They will know the truth about him and someday they will call him out on it.. So just remember what comes around goes aroung.. As they get older and he realizes stuff he will be calling them and saying hey you want to come so we can do this.. And by then it will be to late it will be no I have plans with friend, boyfriend whatever.. SO smile and make a good day.. Because this irresponsibility he is showing to his children will bite him in his ASS...
Sorry for the curse word, just know that is what he is..

Happy is right about the ex and his behaviour but that probably comes as no surprise because if he was an all around great guy, you would probably still be with him. It is hard to watch our kids suffer because of the irresponsible behaviour of our exs but we can't change it, we can just support them in a non judgmental way. My ex never sees his kids and has the same degree of anger (and amount of drinking) as he did the day he left. I know that it is hurtful to our children but I try to be supportive to them, let them know that it is about him not them and not to criticize his behaviour. It is hard...maybe even harder than the step situation, but this is something that we can't change. By modelling good relationship behaviour, we can hopefully help them through this part of their life. I don't spend time worrying about what they think of him, my biggest concern is how this influences their own self worth!