I am looking for as many opinions as possible on this as I really don't know what to do and don't want to discuss it with RL friends as most do not have children or any experience of a similar situation.
This is long but please bear with me as it is not straightforward (whose break-up is?!) but I want to make sure that I am presenting all of the facts.
A bit of background:
I separated from my ex-h over two years ago. He works overseas and does not have a base in the UK as he has been away since he was a teenager.
He has seen the children just once and that was two months after we had left him. The visit did not go well. He turned up a day late for starters, the day after this he overslept due to a hangover and did not meet us in the arranged place at the arranged time. He stayed in the area for a few days and used this time to grill people that I know for details of my life. He went away for a few days and then came back again for a last visit before leaving the country. On this last occasion he was 3 hrs late.
So, none of this was good but I didn't argue with him as I find him intimidating and I knew we would be free of him very soon.
He has done lots of sneaky things that are really besides the point but do matter to me in terms of his trustworthiness and reliability. These sort of things are telling untruths to former friends and family, attempting to sell our UK property behind my back, lying to his solicitor about assets and debts and our marriage, etc.
It has been an 'amicable' divorce in that we never see or speak to each other and I have never confronted him about any of the things that he has done. He does not pay any maintainance and does not stay in regular contact.
He was supposed to visit the girls in November and had e-mailed me in September to tell me so. However, I did not hear from him again until 3 weeks after his supposed arrival date. He had only a few days and wished to see them on a Sunday afternoon and visit McDonalds(!). I told him that we had other plans and so he did not see them and left the country again. I e-mailed him and told him that it would be a good idea to build up correspondence with the girls as he knew little of them and it would be a good idea to get them used to the idea of him in their lives. I didn't get a reply.
Two weeks ago a letter from him arrived, addressed to the girls,telling them how he was going to be visiting them between x and y date. This was a stay of four days.
He did not acknowledge me in this letter at all or ask my permission. The girls are 3 and 6 yrs old so he knew that I would have to read it to them but made no reference to me at all.
So the question is, should I let him see them?
My youngest does not remember him, or even know of his existence as I do not talk about him to her. My 6 yr old does remember him but does not want to see him. I have tried to coax her into it many times but she stands firm and shuts down. She remembers him shouting a lot when she was little and never had a bond with him. I absolutely have not ever tried to poison the girls against im. However, I am at fault for not talking about him at all I suppose.
The problem I have had is not knowing when he is next going to rear his head and decide to be a father to them. He will never see them more than once or twice a year, even if he gets his act together due to the nature of his job/life. He does have the choice to visit the UK more but instead holidays elsewhere. As far as I can see, whilst they are little he will add nothing to their lives as he will not be a constant presence and will not phone or write to them. He already has two children by a former marriage and has treated them in the same way. The difference is that their mother is much more chilled out than I am and lets him pick them up and drop them whenever he likes - which is generally once a year. I also anticipate that the girls are going to freak out and not want to go with him. He is a stranger to them - especially my youngest.They have lots of positive male role models in their lives and everything is going so happily and smoothly. I am worried that he could upset the girls and that just doesn't seem fair.
Thank you very much if you have made it this far. And I really would appreciate hearing any opinion that you have.