I live in the US and my wife and I share a house with my in-laws (and young daughter). We bought the house just over a year ago and myself, my wife and my in-laws are all co-owners. My wife and her parents are Korean and they have a custom of living with parents/extended family.
Anyway, I have been finding that my in-laws have a tendency to make changes to the house or significant purchases, without consulting with me. For example, there was an incident where my father-in-law tried to do some 'repairs' on the brick front steps to the house (which in my opinion made things worse, as he's not a professional stonemason). Then, the other day, without discussing with me, they went and bought half of the furniture in someone's moving-out sale, most of which, in my opinion, is low-quality 'junk' that we don't really need (they have a habit of hoarding all sorts of things, in general).
It's not so much about the money, but the fact that they are doing these things unilaterally, without involving me. I have tried explaining to them that, as a co-owner of the property and given I am bringing home half of the money to support the family, I feel like I should have the right to be included and involved in decisions about the house. However, it seems to keep on happening and they are clearly not getting the message.
So, what can I do to get the message home and convince them that they need to involve me in these decisions? There is a language barrier involved, as my in-laws don't speak good English - their first-language is Korean. So, most of my communication with them goes through my wife (as I don't speak Korean). I have discussed it with my wife several times and once or twice in 'round-circles' with them, but the impression I get is that they give my concerns lip-service - "yeah, sure, we understand, whatever ..", but nothing actually changes, or they forget two weeks later. My wife often seems to take their side (so it's 3-on-1) and says its partly because these things need doing and there isn't time to consult me first. However, I don't buy that, as most of these things are not in any way urgent.
I should probably also mention there have been a couple of times where I lost my temper over these sorts of things and either yelled at them or threw something across the room. I know it's not helpful, but it's starting to really get to me - it's simply not acceptable to me to be regularly 'sidelined' in this manner. Normally, we get on fine on a day-to-day basis, but these sorts of incidents happen every 2-3 months and anyone can be pushed too far (right?).
I am considering that perhaps I should make some 'frivolous' purchases of my own (new plasma TV or guitar perhaps?), to give them a taste of their own medicine and send a message that, if they think they can do whatever they want without consulting me, then that can work two ways. Perhaps that would help them to see things from my point-of-view and be more mindful to include me in these decisions in future?