Updateme! 

If they are paying for 20 people and the kids are counted as part of the 20, then that means they are not getting a reduced rate coz they are kids. Adults and kids are paying the same amount. It doesn't matter if they are tiny humans or adult humans, they are being charged the same. And if that's the case, then their parents should definitely pay. 

About resources, with regards to food, I don't think that should be taken into consideration. You can't just say kids won't eat that much. I've been shocked by how much some kids manage to consume in one sitting. Not all kids eat what's considered "kids' portions" and some adults are good with kids' portions. So I don't think that should be a measure. 

Also managing kids in a boat will be a lot. Unlike adults. And I think they take their share of resources, attention-wise. 

So for me, fair would be each family paying for all their family members and not expecting other families to subsidize them. 

Back to your post, NTA. The parents who want their kids subsidizef are the a-holes.

Decide if you are gonna stand your ground, pull out of the excursion or take one for the team and subsidize the moochers. 

The family definitely understand. They just want to mooch off you. 

Is it only her individual funds going into subsidizing her relatives? Or combined funds? If combined funds, then you need to be okay with that too. Or it doesn't happen. Should be 2 yeses and 1 No. If you are not okay with it, then you guys shouldn't subsidize the relatives.

Edit: If your money (and not just hers) will be used, then it's definitely your place to say. 

If the children are counted as part of the 20, then their parents should definitely pay for their kids. If they can't and you don't want to subsidize them, then cancel the excursion altogether and do something else.

You are not the a-hole for asking the parents to pay for their kids. They should pay for their kids. They are a-holes for expecting someone else to pay for their kids. 

Guess we know who the golden child is.

Keep working hard, OP. Go away for college. I hope you get great friends there who'll appreciate you. 

NTA 

How is that 1700 arrived at? 

Do you pay for the excursion as a group? Or get individual tickets?

Reading your post now, you should have probably remained a single mother. You were probably better off then. Compare your life now, the issues you are dealing with, compare that with how things were before you entered your current marriage. 

So you are the breadwinner? You mentioned all the stuff you do for your step-son that you'll now stop doing. Waking him up, taking him to extracurriculars etc. Does hubby do any of that? Does he contribute to chores? Or is having his mother (who I assume you financially support and has zero respect for you) live with you, his contribution to the household? Is she meant to do his share?

MIL is clearly a huge a-hole. I'm now trying to figure out just how big an a-hole hubby is. And just how much of an a-hole you are to yourself.  

Edit: As to hubby saying step-son is the one who'll suffer, hubby should step up then. Do all the things you do for your step-son to make sure he doesn't suffer. He should also kick out his mom. Hubby is an a-hole for trying to guilt and manipulate you, instead of dealing with his problematic mother. Let this be your hill to die on. 

Question: Why can't husband take a bus to work?

NTA. 

Enjoy your vacation. Your husband messed up. He should deal with the consequences on his own. Stop inconveniencing yourself (including the pickups and drop-offs to work) to avoid him getting inconvenienced. Stop enabling his bad behavior. 

Why does MIL live with you? Maybe one of the solutions would be for her to leave?  

Question:  Why do you pay for everything? Why doesn't husband contribute?  

Question 2: How involved is husband in parenting the kids?

Edited. 

Jane could have been trying to set up OP's wife, have OP catch them in a compromised position. That's why she didn't tell OP's wife that OP and her hubby were on their way back. And intentionally left the watch for the same reason. 

If hubby is out of work, why does OP need stepdaughter to watch the baby when she has to go to the bathroom and things like that? Why isn't the baby's father watching his baby?

NTA. Hubby is a big a-hole and is raising another.

Also, if you aren't allowed to discipline her, then stop funding her life. Let him do that too, unemployed or not. 

Me too! 

Obvious NTA

Wth is wrong with your gf? Why is she so disrespectful of your boundaries? 

All secrets? Does she overshare her personal stuff? Her relationship stuff with her bf? Or anything that portrays her in bad light? Or is she only very generous with info that involves other people? 

Coz if she's just yapping about other people especially stuff that's bad and is a vault about her stuff, then she's not really bad at keeping secrets. And it's just her being controlling and  manipulative. Using the info she has on her friends as a weapon. Spilling secrets when it benefits her in some way. Or when she needs to keep you in check.  

I also think C might have been interested in you. Or you two might have been (or A just thought you were) getting too close for A's comfort. And A ended the friendship with C coz she didn't wanna share you with her. And then fed you that bs reason about C making her choose.  

Like someone else said, there's a reason she doesn't have female friends. Probably doesn't like sharing any kind of male attention with other women. 

That you think that proves just how smart she is. She's successfully played you.

She comes off as manipulative and exhausting af. And whatever she told you about her female friend and the reasons for the friendship ending is probably a load of bs. 

Question: Are you straight? If you are, have you dated anyone during your friendship with A? And if you have, how does she act when you are dating someone? How does she treat your dates/girlfriends? 

True.

And if OP's dad enables that then he's either completely spineless or an even bigger a-hole than I thought. And OP would be better off living with her grandparents.

Your house is clearly not big enough for your step-mom to have her own office. She should have set up a desk in her and your dad's room. 

Plus your stepbrothers are only 2 years apart. And also grew up together. The gap between you and your stepsis is way bigger. You two shouldn't be sharing a room just so your step-mom can have a home office.  

She's incredibly selfish. And it was also wrong of her to make all those changes while you are away.

She's a huge a-hole. And if your father is enabling that assholery, then he's equally to blame.  

Plus how is gonna make you want to have a relationship with her and her kids? Step-mom's behavior is standing in the way of a potentially successful blended family.  

NTA

OP is wrong about SIL being completely unaware. OP mentioned her hubby is always an afterthought and SIL gets the attention. OP should stop absolving SIL of blame. She's as much to blame as her parents are.

OP and hubby should stop indulging them. Set boundaries now. Or things are just gonna get worse. Especially if the divorce goes through. I'm thinking OP and hubby will probably be constantly asked to babysit while MIL takes SIL on shopping and spa trips coz she's sad her marriage ended. 

Hubby cares more about Dick than he does about OP and their children. He has proved that over and over. And OP doesn't seem to be getting the hint. She should really take hubby on his offer of divorce. 

Y.ta OP to yourself and your kids. NTA, overall. 

Updateme! 

Or the bigots think they married "one of the good ones" and continue to look down on the rest of their partner's race, gender or whatever.

Her reasons for not wanting her kids to learn urdu are not sensible. A sensible conversation might be beyond her.