To have still gone out yesterday?

It's not about Stepmum not being bothered with their partners kids. It's that Mr lazy dad doesn't want to have to actually do the work involved in actually parenting his own children and is annoyed when his wife doesn't play ball like he wants her too. That's the issue as I see it.

Their dad can do something nice with them!

Typical lazy man. Just wants to palm all the work of his kids onto you...under the guise of mother's day.

If the OP had something like tickets to a Peppa Pig Afternoon Tea, with her Mother and Daughter on Mothers day... would people still think she should have included her step children?

And step children don't pick the situation they are put in!

Maybe OP's mum just wanted to spend time with her dd and dgd on Mother's Day.

Hello OP
You did the right thing. Mother's Day is the one day in the whole year that Mums get fussed over and prioritised.
You treated your Mum (correct priority) to a lovely meal out with her daughter and grandchild. As a Mum yourself, you also deserved a lovely day out on this day.

DP could have easily made it up to SC with an alternative treat/outing, but chose not to - and this is his decision and he cannot blame you for this. It is absolutely not fair to expect you to change plans with your Mum just because his Ex had to work. I would not give it a second thought.

So he didn’t want to come when it was just you and your child but when he has to have his alone suddenly he fancies it 🤔

But the dad and DSC were all going to go not just loading the DSC on to the OP

Interesting how a lot of blended families are so devisive.

Marry somone but can't be bothered much about his/her kids.

I knew I couldn't be a step parent, so didn't date anyone with kids.

Why put yourself in that position if not interested in the kids.

Glad you kept your plans. Yanbu
He didn't want to be alone with kids when he had a quiet day planned.
Wanted you to help look after them.
Typical
Lazy
Seen it for years with various friends DH etc

I think if you've already got plans that's fair enough and DH should have taken them out

No YANBU!

You already had plans, presumably you booked the restaurant, and as it's Mother's Day I doubt you would have been able to increase the number of people coming at the last minute.

It would have been a great opportunity for him to do something with his child. Why do some men only want to do things when their partner is there too? He expected you to drop your own mum on Mother’s Day as his child came, sorry but no I wouldn’t have changed either.

When he decided not to go in the first place, did he worry about hurting the OP's feelings?
I suspect not.

And it's okay to want to do something with your own mum and not include your partner. Particularly when he just wants to come because he cba to look after his own dc without help!
Couples don't need to be joined at the hip 24/7.

This is why I couldn't have a blended family.

You absolutely did the right thing. Sounds like dh didn’t want to spend time alone with his own children.

If he had no idea you were going out, sure, I can see that point of view. But if you've planned something with other people, he's known about it and been fine with it, but then, on the day he suddenly changes his mind and becomes "hurt" - that sounds like manipulative and controlling behaviour.

Because perhaps he was hurt or offended that she didn't seem to want him to go for the meal?

I agree that the restaurant isn't the point.

But it could just come down to him feeling hurt.

If it were me and I was going out with my kids and then on the day my partner seemed to want to come too with his child then I could see why he might feel hurt or offended if I didn't want him to.

Well no, she didn't want him to completely change the character of her outing. One he'd been absolutely fine with when it was just his children who were also her children going along. I think she's been pretty clear on that.

So if you're aware she didn't want them there at all, why does it make a difference whether she'd have to cancel or not? OP's argument is that she didn't want to change her Mother's Day around when her DH was quite capable of picking up the slack he'd agree'd to take on at the last minute for his ex. The restaurant isn't really the point, though in OP's opinion they would have had to cancel (and, frankly, if I'd had to be squashed in under the stairs because other people wanted to crash the meal at the last minute, I wouldn't be happy with that, either.)

The issue is - why didn't the DH do something else with the DSC since OP HAD PLANS already.

Because by the sounds of it she didn't want him to go and he obviously became aware of that.

If she seemed open to the idea then perhaps he would have phoned, but when she wasn't open to the idea then of course he wasn't going to pick up the phone and try to add himself and the kids to the table.

So he didn’t want to come for the meal when he thought he was getting the day to himself ?
But when he realised he had to entertain his DC he decided he’d like to come ?
YANBU

Maybe you’re right and she did just assume. But if it’s a case of someone should have checked - why would phoning up and checking be her job? He could have done the leg work just as easily, even if he’d had to pass the phone over to her to actually change the booking.

I read her posts and didn't see that he wanted her to cancel and it seemed like she just assumed that she'd have to go to another restaurant (unless I missed one).

It's possible that she could have phoned and they would have said yes we'll squeeze you in. Or else they could have said no but by the sounds of it she didn't ask.

I've actually managed to get tables at restaurants twice on mothers day without booking even though they were apparently booked out. Once I got put under a table that they seemed to have just found somewhere and put under the stairs but I still got in all the same😂

They couldn’t join because it was a booked table for Mother’s Day and most restaurants can’t magically fit in an extra three diners without notice on likely their biggest lunch service of the year.

He wanted her to cancel (which is a shit thing to do to a restaurant at the last minute) the special meal she’d booked for her mum, herself and kids and find a different restaurant - likely a poor one given, as previously stated, it’s Mother’s Day, there would be at least 6 of them and there was no notice - instead.