I had been using this site for a long time to help my circumstances, even though I didn't ever find the courage to post. I thank you all for helping me reach my decision. 
 

I've finally decided to end our relationship. I moved out of the family house a few months ago and now it's up for sale. Can't believe I actually did it but the whole guilt ridden Disney Dad, entitled skids, ever present BM and him never wanting to consider my feelings took its toll.

I came into the relationship very naively. I wanted to have a relationship with his kids and wanted to support my finance with a civil relationship with his ex. How wrong was I?! I was literally put last in every single situation. I have one son (12) who I have shared custody with his dad. We have every other weekend and share the weekdays. I don't contact my son's dad unless it is absolutely necessary. We have a set routine so we know what we are doing on any given day. My finance would choose to have his EVERY single weekend plus weekdays on top. When we first got together he made sure he had weekends free but as soon as we moved in together it was every weekend all weekend. I work all week but he didn't understand that I may just want to relax without any kids around every so often. I compromised on a Friday night/Saturday morning once a month but he basically said I should be ashamed of myself for asking him 'to have his children less', even though he could have easily swapped a Friday night for a Monday night. Even worse was that he would arrange nights out with his friends at the weekend and still expect his kids to be at the house (Ages 11 and 13 so fairly independent). But I would have just loved some peace every now and again! 

He'd also just randomly pick them up in the week and not even bother to let me know. So I'd come in from work thinking we had the house to ourselves and his kids would be over. I couldn't even book time off from work in advance knowing I'd have the house to myself because my finance would just say 'I don't know when I'm having them yet'. The 11 year old would stick to my finance like glue the whole time he was over so I'd just be pushed out. I can't count the times that I've been sat in the bedroom alone at the weekend. One time I thought we could have some drinks together in the garden and some adult conversation but his son sat with us the whole time talking to my finance. He stayed until we all went to bed at midnight.
 

The amount of times I'd be dropped for his kids was ridiculous. I'd plan a meal or we'd have reservations and he'd just drop me if the kids wanted to come over that night or if they specifically wanted him to take them training. I don't necessarily think that kids wants should be put before everything else all the time, needs yes, but not wants. 

He wasn't great with my son either. He wouldn't even pick up a birthday card for him, but I'd surprise his kids with balloons, presents and a cake for his. One time he came back from the shop with a treat for his and nothing for mine. He apologised after, saying he was thoughtless but still......

Another thing was his relationship with his ex (BM). She was initially very unknind about me and my son (despite the fact she didn't know us and they had been divorced a year before we met). He never stuck up for me, just ignored it because he didn't want her to stop him seeing his kids. She then was very dismissive about me and never acknowledged me or our relationship. However, they would message each other pretty much daily about the kids. Really petty stuff too, like 'remind son to brush his teeth' - he's 13 and has a phone, so why she couldn't message him directly! I found out he'd sent photos of our family trip away to her (while we were away) and one time the kids let it drop that they had all been out to watch a movie together for one of the kids birthday. My finance had completely lied to me about that. When I found out about that I attempted to create some boundaries and said I would like him to only message her about the kids, nothing personal and not to go out as a family. He agreed and was very sorry but a few years down the line they were still messaging about his new business and different things.

So in conclusion, although actually making that break was hard, I do still love him but I feel so much more relaxed in my own home. I would be massively wary about getting involved with anyone else with children again. It's scarred me!