to dislike the 'blame culture' in my household

[dollydoops]

I live with my DP (also female) and her DD (16). My DP collects spare change in a big jar which, when it gets full, gets taken to the machine at ASDA to be exchanged for a voucher (Coinstar?). This is DP's jar, no-one else puts money in.
Today DSD and I were upstairs talking. DP shouts from downstairs 'Who's taken money from my jar?' Comes out of kitchen brandishing jar, which does look a bit empty. DSD shouts 'Not me' and I know it wasn't me so I shout 'You must have taken it out darling'. At this point DP begins grumbling, saying 'No-one ever admits to anything' and 'It's always my fault' etc.
AIBU to think DP was being a bit out of order here? I can't quite put my finger on why it bothered me. I think it was being sort of 'lumped in' with DSD, and then the implication that 'someone' had taken money but wasn't saying so... sorry, I know this os very trivial but AIBU, really?

You are and you are not.

She's a right to say that if it has been dipped into - its not unreasonable of her to ask. She might have specific concerns if it is DSD (what she's using it for, why she couldn't ask, etc) which make it perfectly reasonable for her to want to ascertain who did it ("Blame")

In general, a blame culture is a bad thing so YANBU but I dont think your partner was being U in this instance...

Well, clearly someone had taken money out but wasn't saying so!

Can you blame her for being pissed off?

You didn't take it.

She clearly didn't take it - she wouldn't use it then wave the jar around and say someone had dipped into it, would she?

So that leaves...?

The daughter.

Or any visitors to the house.

It needs sorting, anyway.

Lock jar away? Move it to bedroom?

hmmm, yes I see your point if DSD had been likely to take the money, but I really doubt it strongly. But nonetheless, I sort of felt as though DP should ask us separately- because I'm the adult and DSD is the child, and 'grumbling' like that made it sound as though DSD and I were both 'not admitting to' stuff. Maybe I am BU...

Nah, not really. You felt like she treated you both like naughty children when in fact you are her partner and her equal.

On a side note this amused me as it's an odd thing to shout.

"so I shout 'You must have taken it out darling'."

I imagined that as a light, tinkling trill.

Or a narky bellowed " YOU must have taken it out. 'Darling' "

Well it's her daughter and she must know it was her. Maybe she just didn't want to think about the fact that her kid is obviously stealing from her

Well, her DD is 16 ... when would you like your DP to start treating her like another adult? So I think YABU to object to being 'lumped in'. YANBU to think it's a bit petty to treat either of you like that, though.