@teardrop2021
It may not be ops fault with the current set up but shes not doing anything in particular to make things easier or to accommodate it.
Why would she? It doesn't benefit her to do so. Most SP take the lead from the attitude of the biological parent. If he's not bothered to be in his DCs life any more than once a month....why would an unrelated romantic partner of his be.
The fact is her dp does have two children who should be as much of a priority to him as this baby.
They should indeed and I don't disagree with you for a minute, but this isn't the case. The OP can't make him do more, that's 100% on him.
Most women don't go looking for a partner who has children, so having a partner with kids that he is barely involved in is the next best thing. He could easily have friends who have known him for years and if he wanted, they'd never know he had kids...due to how little they're a part of his day to day life....this is not the OPs problem though.
Shes got to learn that they were they before the baby and she's needs to accept that contact will have to take place and she can't make demands simply because she's had a baby
I don't think the OP was making demands tbh. Just expressing her anxiety over being left alone with the baby. Her priority is her baby as one would naturally expect.
He's a parent in name, but the current set up...where he sees his kids for less than 30 days a year, doesn't really cut it as a parent.... and attempts to defend it are again human nature, as nobody wants to hear people say their partner is a dead beat dad.