I know this is going to sound really petty but I feel really sad about this. I suppose I just need to know my place.
DP has 50:50 shared residency of his 3 boys. We blended our families 2 years ago and on the whole it's been fine. Just normal family stuff. We have taken each others kids into our hearts and we are one unit.
I have a very good relationship with the boys mum. She asks for my help when needed and vice versa, we share pictures of the children on our weeks to keep each other updated with what they are doing.
DP and his ex wife have basic communication but ex wife and I seem to have struck up some kind of relationship - not friends, but I am lucky that she acknowledges me as a part of her dc life.
The dc are very involved in sports - mum is big into running and therefore the boys are involved with that. DP is big into junior football and the boys are heavily involved.
DP doesn't get involved in the running and ex wife has never been to a footie match or taken them to tournaments or training.
I am involved with the football club in so much that I volunteer for the club and also ferry the kids to all games, along with dp. Sometimes we need to be in two places at once so I take eldest to his commitments and dp takes other two.
I also look after the other dc at home which allows dp to do his footie things 3 times a week 2 hours at a time
In our house footie is a big thing. And I have embraced the whole thing, it's actually given us a really good social life too.
So big cup final day yesterday and all and sundry were out to support. For the first time ever ex wife showed up with her husband which was a real treat for the boys as she has never expressed and interest before
I introduced them to everyone and it was a good day. DP manages the team and we have lived and breathed this cup final for weeks.
So we won, and it was great. But I just felt really deflated because the boys just wanted mum, DP was busy doing his thing and therefore I felt sidelined. What should have been a really good celebration turned out to be (for me) a harsh reality check that I'm surplus to requirements and it made me sad.
I sound really selfish I know I do, but whilst everyone was cheering and hugging their children / partners after a good win. I found myself on my own, despite being the one who has been there the whole time 
DP left me to it as well, he was just doing his thing and it wasn't until after the presentation that he actually came anywhere near me.
I was on the sideline looking in at him, his ex wife and the boys - a lovely little family unit.
It's lovely that the boys can see their parents sharing the same as them, as I said it was a real treat for them. I just feel deflated.
So, time to reevaluate my role in all of this and start to manage my own expectations. I am just dads girlfriend.
I love those boys and don't want to replace mum, I couldn't possibly but the football thing was our thing now I feel like it was just an act because I happened to be there at all the other events.
I'm not sure what I expect to get out of posting this, maybe just getting my feelings out.