Not your circus, not your monkeys.

Very occasionally, when in a particularly gracious and generous frame of mind, and if she asks really really nice, you might, from time to time, agree to look after the little dear. But to be expected to do this regularly, as a matter of course--nuh uh.

I hope you slapped your thighs and roared with helpless laughter. Her son is HER responsibility. IT's up to her to see he has a sitter if he suddenly (as it appears here) becomes incapable of staying alone for a couple of hours. She doesn't get to dictate how you spend your time and her refusal of your first two suggestions was simply ridiculous. Why is she trying so hard to needle you? Are you not getting enough time together? IS she afraid that if you continue with the band you might give up your job and she'd be carrying all the weight of the household single-handed? Does she feel that youi spend more time with your friends than with her? Does she feel that her role in your couple has been reduced to money and domestic? Look for the root cause because I think this tantrum was just a symptom of something bigger. 

I take care of my SDs full time since they live with us. It was only while he was at work but then it turned into even when he's home. Getting them up for school, on and off the bus, every meal cooked, parent teacher conferences, school dances, homework, school shopping, and even going with DH to drop off/pick up girls to/from their 5 hour visit 2x a month (if she even gets them) visits with their BM. On top of having our son and another due in Dec, I don't have any time for myself. If you don't put your foot down, same will happen to you.

Hmmm. She doesn't like you being in the band. Why? Does it take away from her ability to have control over you? 
 

There are lots of obvious solutions here, including him staying alone since he's been allowed to previously, or her dropping him off at your practice, or whatever. But this isn't really about who watches SS. It's about her wanting to keep you from your friends. 
 

Is she abusive and controlling in other ways? If she were a man, this attempt to isolate you might be more readily obvious. People don't tend to think of women as being abusive in that manner. 
 

Go to your practice and let her deal with HER son. He's not your responsibility. And don't let her anger or manipulation control you. 

My husband is a professional musician. It can be difficult. I agree there is more to this then just watching the son. She seems to have an issue with the rehearsal itself. You need to have a discussion with your lady about responsibilities and expectations. 

The one with the kids, who screwed up there first marriage,  who the BF, the one they had the kids with.  Will not stand up and take care of his kid.  Is golden. But you have to make SS the number one priority.  Why isn't BF doing 50/50 schedule in parenting?  His kid should be his number one priority !! 
Be cause BF is a failure  You have to make there kid your priority.  Back to Disney Mom   
Why are not Disney Mon ever discuss on these boards.  There kids make there own sun and lights up the world for everyone.

Band wife here. (What instrument do you play? or sing?)

This is your hobby, and may become more than that. Not playing would be like asking you to stop breathing, I bet.

But is something else going on? LOTS of band wives feel like the band is a sort of mistress. You spend time and money that maybe you don't have, are gone a lot because of it, she's left alone more than she'd like, and it's not fun when other women flirt with you during gigs. Band wives can also be clickish and unwelcoming to other band wives. It can be like stupid high school girls all over again.

If she feels like the band is too much of your life, then maybe the childcare thing is a smokescreen. Maybe she just feels abandoned more than she anticipated. See if there's something deeper going on.

But, in the end, it is not your job to watch her kid, and you've come up with several reasonable alternatives that she's unreasonably discarded. That's why I think something else is going on.

Welcome to ST.

Your step sons bio mother AND bio father are 100percent responsible for the care of their child.

She can call her ex. I bet he would be thrilled to take his son.

GoodLuck

Get him some noise cancelling headphones.. grab his laptop and take him with you to practice..hahaha.

I don't understand why he normallycan be home for 4-5 hours by himself (which is kind of a lot for a 10 yo though)... but 1.5-2 hours now isn't?  

Is there any flexibility with your band to start a little earlier so youwould be done earlier? 

It really isn't your place to figure this out.. but you are probably more aware of what her real options are than we are.  It isn't your job to arrange childcare with your sister.. but I can see her thinking the answer might be yes to you before her.

In the interest of home harmony.. I might see if my sister could do it.. and put this behind me... if this is literally a rare thing with her.

This sounds like a symptom of a bigger issue.

Steplife works best when everyone understands what their role and and responsibilities are and aren't. Your wife is trying to force you to handle something that is HER responsibility. The real question is, why is she so very adamant about it?

I stopped reading at this part, "he needs to be my #1 priority and that all else follows." I'm sorry, your wife as the parent is absolutely grateful for any help you give her, takes your schedule into account and then finds a solution herself. It's simply not your responsibility and it's an obvious power play move on her part. Your boundaries need to be firm with her.

Wow, she sounds like a peach. It sounds like she is treating you like a child and unfairly as well. 

I would absolutely refuse to miss my practice for this. You should be asked not told to watch her son, her responsibility. 

Is this a hit and run???
 

The OP has started exactly the same thread on the Step parent forum on Mumsnet. Got lots of good advice, posters asking questions to clarify understanding, and then just disappeared. 

OP,  if you are still there, no the SS is not your responsibility,  but please answer why a TEN year old is being left alone for 5 hours a day. 

A marriage where either of the spouses put children above the marriage and each other is doomed. Don't waste any more of your time on this failed mother, wife, and woman.  

Give her clarity, you WILL have your rehearsal whether she wants you to or not, she WILL make arrangements for her son, and she WILL gain clarity that nothing takes priority over your marriage and each other, including children regardless of kid biology.  She also needs clarity that you both need lives as individuals within your marriage.  That includes your band, and whatever individual interest she may have, and individual friendships that can include both of you upon occassion.

If the Skid spends a couple of hours a day at home alone while you and his mother are at work, he can be home alone while you and your band rehearse.  If your DW takes exception to this.. tough shit.

smh