the boy

[richardhh]

AIBU to be annoyed when wife backs kids (boy) rather than me?
Boy (7) shot sister (10) in head with foam dart gun.

I told him not to immediately before he did, turned out not to be loaded but he still "shot" when told not too.

I sent him to bed (it was around his bed time) but wife thought it wasn't an issue and argued point in front of kids, AIBU?
If she lays the law I back her 100%, really annoyed at this one!

I actually agree with your point in your OP. Regardless of whether he did or didn’t shoot the dart, your wife undermined you in front of the children. She should have waited and had the conversation afterwards when you were alone.
It always has to be a united front.
From that perspective she was wrong.
If he knew it wasn’t loaded then he didn’t shoot his sister though.

Maybe op isn't aware of the 'ds, DD, dw' etc on Mumsnet and just used boy as a name.
I don't think he's being unreasonable, the child deliberately ignored what he had been told and shot the gun at his sister. Getting sent to bed a bit early isn't a Draconian punishment.
Also, best practice to at least pretend to back up the other adult, unless it's really gone over the top.

this sounds like homer simpson wrote this when he refers to bart as 'the boy'. sounds like there are bigger problems in the family than the one mentioned in opening post.

mam op could have said son / step son.

YANBU - You told him not to do something, he went ahead and did it anyway, so you followed through on his punishment.

I think you need to discuss issues like this with your wife once the kids are in bed - it's horrible for them to have to witness their parents arguing.

@littlepaddypaws true.

YANBU. Your wife should have backed you up instead of fighting wth you in front of the kids, even if she thought you were a bit OTT. She should have discussed it with you afterwards in that case.