I totally sympathise with you as I am going through the same. My ex is horrible to me or totally ignores me and bad mouths me in front of our DS. He tells our DS that I should not have a boyfriend - which I don't currently - because I should love only our DS whilst he sits there with his girlfriend of 4 years and his DD from that relationship!!! Good for the goose???
He allows him to do or watch inappropriate things but will not enter into any discussion about it. If I try to discuss anything he screams abuse or sends nasty emails so I fume in silence.
His GF is just as silly and my DS knows how much they both hate me. He ran up almost £20,000 worth of debt which despite him telling a court that he ran this up without my knowledge, I was found jointly liable - car loans and bank loans, house payments etc which we had both signed for originally - and he skipped out on most of it and left me to pay it all because I have a conscience. My solicitor has just told me that I would be advised to accept his current offer of settlement which will barely leave me debt free and give me nothing in my hand to make up for the years of struggling to pay off his debt and raise his son alone.
He has not paid maintenance for the last 4 years so I went to the CSA and was awarded a monthly amount from December 06 but have yet to see a penny. He never bothered with the 1st payment, bounced the next two and then when they told him they were taking 40% of his wages to cover some of the arrears he managed to negotiate a smaller amount and I still haven't had anything! I have to complete a 100 mile round trip to pick up DS when he visits his dad once a fortnight though he does collect him so I should be grateful it's not a 200 mile round trip!
I am hoping that he actually does pay the money he offered in settlement so that I can finally put this all behind me and get a divorce from him but will still remain sceptical until I see the money in my account.
I frequently think that our DS would be better off without this horrid influence from a man who cannot be bothered to spend much time with his DS and only does so for appearance sake and to annoy me but what can I do? I would likely make the situation worse if I stopped him because it would give him something to fight about and coould come back to haunt me later if our DS asks why I wouldn't let him see his dad.
I would not advise stopping access and just go through all the correct channels for maintenance. My mum says 'fight the battles you can win' and I would think that stopping access would only result in everyone losing.
In Scotland you can apply for your decree absolute 6 weeks and 1 day after your decree nisi has been granted.