Would you have him go?

My little boy LJ turns 3 on 2nd of Feb and we planned a party on the 1st. We have a tradition where we do a party then the actual day is all about them. We do it for each child and they love it. Because there are step children in the family we schedule bday parties anytime within a month of their bdays so everyone can come and that’s why it’s important the actual day is strictly about them because sometimes things have to be scheduled around all the schedules. We plan early and are respectful of the other parents times (both husband and I had kids previous to the marriage). This year we planned LJs weekend and included the siblings. My older son Jax was already scheduled to be here for that weekend per court order so we didn’t need to ask the other parent anything.

At my Jax dad’s house he has another sibling Bryan born the day before LJ. Dad has Jax the weekend before and his bday was never a huge deal to dad so I didn’t think much of Bryans as far as scheduling LJs. I just thought they’d party with Jax the weekend he is there. So we plan it, book a small place and planned activities on the actual bday. Now dad wants half of that Saturday (day of party) or Sunday!(LJs actual bday) with Jax to throw their party. I asked why not party the weekend Jax is there and he said that’s too far from Bryan’s actual bday and he wants Jax there and it has to be one of those days. Jax said he doesn’t want to go because last party he was bored and treated bad (won’t go into detail but had him in tears). Dad says just a few hours but is never on time so I already know it’ll be half the day and we won’t have estimated times he’ll be gone so we’d essentially spend the day waiting around for him. Jax already hates being there more than required which makes being a good coparent hard because I want to be a good mom too. I definitely said no Saturday but would you make Jax go on Sunday?

Important info:

Dad is always late and never does pickup or drop off on time and is off by at least an hour each time.

He also has never answers the phone and does not update about times.

Jax is scheduled to be there the weekend before and after so this is the only weekend we have for LJ.

I had no idea Bryan’s bday was the day before as Jax wasn’t invited to the hospital to meet the baby at birth and it was never mentioned, they just celebrated the week before last year which i assumed was the plan this year.

And finally, it’s hard for me to decipher when I’m being fair or not as he was my abuser, manipulator and often makes it out to be that I’m a bad co parent if I let him miss things in place of staying home and doing what we planned.