Very long so apologies in advance!
Some may remember my previous posts on here about DS (2, 3 in Jan) and his dad.
Trying not to drop feed, exP was emotionally abusive when we were together and physically on a few occasions (police were never involved). He was barely at home out every weekend taking drugs, cheating, god knows what else. On one occasion he called DS a 'fucking retard' when he was around 4/5 months old.
We split up 2 years and 2 months ago, and up until last September he had contact each weekend, Saturday 9-6, then changed to Fri 6pm to sat 6pm in April 2015.
I facilitated this contact, did all pick ups and drop offs (45 mile round trip), provided everything DS needed in terms of food, nappies, clothes, bottles and formula (When he needed them). I received no maintenance as he wasn't working. He refused to have DS on various occasions when he'd been arrested, was hungover, still partying, or even on one occasion had sunburn 
Last September I wrote My car off, therefore was unable to take DS to contact. He took this as me stopping seeing him and because very abusive, calling me names, saying DS probably wasn't his, then didn't get in contact for a month. He then got back in touch apologising promising the earth etc. Never ended up materialising as he got drunk and started sending abusive texts and emails. I informed the police and blocked his number/email.
He has been in touch a few times since then, none of which to enquire about DS, just to give me grief, insult me, and inform me that when he did see DS he would tell him 'his mummy is a cock loving slut' and take him and not return him. Each time I have reported this to the police.
I received a letter requesting I attend mediation in May, where then I spoke to a solicitor who advised me to decline this on the grounds of his emotional abuse which I did. We then wrote out to him offering supervised access in a contact centre, which he did not respond to.
Fast forward to today, I receive a phone call which is him. He apologised for everything. Asked how DS is. Told him he is fine, and doing very well at nursery, bright etc. He then asks how he can see him, says he will jump through every hoop. Informed him I don't know where to go from here, as this is the exact same conversation we had last year. Asked how long it would be before he didn't get his own way and became abusive again, and lo and behind 'he's changed'. Asked him why he never responded to the solicitors letter and he said 'my mates said that's where crackheads see their kids so I didn't bother'... wow.
Unsure where to go from here, he doesn't want to go through 'all the legal bullshit' as he calls it.
I don't want to deny the chance for DS to make his own decisions when he is old enough. However I have to protect him from being used as a pawn against his Mother, and myself, from the stress and anxiety this 'man' puts me through, and the threats he has made to not return DS to my care if he does have contact.
Any advice would be so appreciated 