7 tickets for Holy Communion - only one for Dad

[ThisMustBeMyDream]

My OH's daughter has her Holy Communion shortly. Today he has been told he can only have one ticket for the family reserved seating by her mother. The tickets have been given out by school, and the maximum available is 7 - she is keeping 6. SD's mother works in the school. My OH has been told by Mum that the wishes of their daughter is that it is mum, her partner, big sister, her grandparents and great grandma and dad that sit in the family reserved area.
Me, I'm fine with that. Fully expected that her mum would do this. I've kept a VERY wide berth for the 7.5 years we've been together. She behaved very badly for the first 5 years of SD's life, and I have no desire to involve myself in any drama.
DP feels it's just another way he and his family are pushed out of SD's life. He felt that he should of been offered half (well, at least 3) of the tickets so SD could have his side of the family there.
I absolutely agree with him that she is wrong in the way she has gone about it. But the best way is to just ignore it. Asking SD who she wants there is pointless for him as she will just repeat what mum has told her. I've told him he can have who he wants there still, but they will just be in the side Chapel - not in the family seating. He can choose if he wants to sit there, or with his family in the other area. I haven't been at a Holy Communion before though, so I'm not sure if being seated in the side Chapel will mean he isn't included in events. Maybe someone here will know?
My question is, has anyone managed to overcome this kind of behaviour where dad is always second best and not included in big life events? Her mum has been better in the last few years, and she has apologised for all her past behaviour. However, actions speak louder than words - this kind of behaviour has been rife throughout her life. At her Christening, mum had her then partner walk down the aisle holding SD as if he was the father. DP wasn't allowed to take his place at the alter. I could go on and in with examples, but I'd be here all day...
I'd just like to advise and support my partner in how he feels about his role as her dad. He feels incredibly sidelined really.

I should clarify that really. What he means by not wanting to cause issues is that it could affect his daughter if mum has problems in her work, then mum changes SD school, or mum no longer works there which would be less pleasant for SD. Basically, he doesn't want issues for SD.

My own experience of parents separating was terrible - my dad caused issues for my mum at her school, where she was a teacher and I was a pupil. Mum felt she had to leave. As a result it massively impacted me throughout my life (I was part way through yr5 at the time - moving to a new school as a 10 year old girl was a horrific experience and impacted my high school years too). I think my experience makes DP even more cautious.

He doesn't have to sling mud. My DH hasn't said anything bad about his ex just that communication between them is strained. I get it must be much more difficult with her working there but your OH has as much right as she does to attend and having and input in his DDs life. I agree with the poster that says contact the priest directly. Probably better as he's more impartial. I definitely think he should still have taken SD to the preparations that landed on his day. He should have been more proactive in finding out the schedule for that and taking her along regardless of what her mum said. We've never trusted a word that comes out of my DHs ex's mouth and always check everything directly with school/doctors etc.

Is there a celebration afterwards? Is your OH contributing to the costs of the day?

My friends son is making his communion next month and has arranged a party afterwards. She is paying for everything, his suit, the hall, bouncy castle, food etc. Her son's dad and his partner are coming. She asked her ex to contribute and he said no because the £140 a month he pays in maintenance is enough according to him. 🙄 He then had the cheek to ask if all his side of the family were invited and my friend's told him no since he wasn't contributing anything towards the celebrations why should she pay even more to caterer to his family.

I think he very much errs on the side of caution even telling the school that things are strained. I'll see what he tells me this evening as I know he will either speak to school or priest today.
As for a celebration, it is her mums weekend. He'd never be asked to attend anything (and nor would he want to). He will be absolutely kept in the dark of mums plans anyway - so hes no idea if something is planned. We will do our own celebration instead on our weekend with family. We've always done our own celebrations for birthday, Easter, Christmas etc. This is equally her home and we treat it as such. All occasions will be marked here as they would be for my own children.

Don't blame you. We've always done separate celebrations because we can't bare to be in the same room as that woman. It also saves arguments over costs etc.

Your obviously not catholic, communion classes are for the children and their parents, the church would encourage both parents to attend, being separated dose not stop either parents from actually being parents, that’s strange to think one should be excluded just because it’s not their day.

Presumably the child has grandparents / great grandparents on the dads side that might want to attend.