XP has rarely seen DD since she was 6 months old and hardly at all this last year. He has been trying to sort his life out. 
On the rare occasions he has managed to see DD, I have tagged along, mainly because he has never shown an interest in seeing DD alone, and because she sees him so rarely, she doesn't really have a relationship with him. I mean, they have fun, but she barely knows him. 
XP still harbours a lot of resentment over the time we were together and throws this up in every conversation we have.
Anyway, he has got into a habit of not seeing DD for months, when he is in a relationship, then as soon as he's single, he emerges from wherever he has been and wants to see her again.
I have bent myself into a pretzel shape trying to keep contact going for 3 years, to no avail. He sees her once, then nothing for months. He wont see her, or phone to talk to her, he doesn't skype with her, nothing. He wont even text me to ask how she is, he just makes no effort at all, until he wants to see her again.
I ring him, text him, literally begging him to see her, but he is always unable to, because he's trying to sort his life out. This is his mantra.
It has always been this way because DD misses him, brings him up unexpectedly in conversations, and wants to see him, yet he can't be bothered, although he lies says he misses her.
He is a thoroughly self centred rubbish father, and I would do anything to change him but I can't..I know, I have tried.
Anyhow, he hasn't seen her, or made any sort of contact with me to arrange seeing her since last September now. I have phoned him/texted him and get the usual trying to sort my life out bollocks, and DD has been intermittently moping asking for him since then. DD remembers what we did the last time she saw him and wants to see him and do XYZ again. It is heartbreaking. 
I have consistently asked him when he will see DD next, and he constantly moves the goal posts, first it will be 'I don't know, when I have sorted myself out', then he finally said it would be last weekend, then he couldn't do that, so it was going to be this week, during the week, now it is this weekend.
He has a new teenaged girlfriend who has a child by a previous partner, and suddenly, he has agreed to see DD. 
Now I have told him DD needs consistency, and he claims he will see her every weekend from now on. I don't believe that for one minute, he has said all of this before. He is insulting to me on the phone and just rants about what a shit mother I am and lists all my previous mistakes, yet wont acknowledge he played any part in anything that has gone wrong. He is a victim through and through.
He wants to pick DD up, and take her out with him alone, which is unheard of for him, for a couple of hours, then return her, but I just know DD wont see him again for another few months again and she will be heartbroken, moping by the window for days on end again, incessantly asking for him again for weeks. (She has a v good memory.)
DD misses him, but is kind of on an even keel again since she hasn't been messed around by his inconsistencies (sp) and I'm not sure I want to rock the boat tbh.
I know people say she'll realise what he's like if he keeps letting her down, but that means she has to get hurt to realise, and I don't want to put her in a situation hoping she will be hurt by him, so she can see what he is like. 
I want her to remain innocent and unaware of his royal shittiness for a bit longer. 
I don't know whether to take her to meet him and his girlfriend who will probably be hiding round the corner so they can break DD's heart all over again in their quest to play happy families for 2 hours or to say 'You've not sorted your life out, you've shown me no indication that you can offer DD consistent contact, so fuck the fuck off!!'
In all honesty...WWYD?