It seems as though I have inadvertently upset a family member. Things have been very tight financially for DB and his DW. For example, only being able to afford to go abroad on holiday once a year, having to buy supermarket's own produce, having an old car etc. DB is doing temping work at min wage and his DP is on more, but not earning a wedge. They live in a small house, don't have much disposable income. They can only go away for the weekend maybe three or four times a year max, they don't buy many new clothes and things like that.
Apparently I've been rude because I make a lot of comments about how I know they haven't got much money, and told them a new car will financially cripple them. Joking about how DB's wife shouldn't get her hopes up about Xmas presents from DB because of their financial situation isn't very nice either according to DB. They had a new carpet fitted and I jokingly asked how they could afford it, because DB hasn't got a real job and they've got no money. Apparently I'm being thoughtless and rude. 
I'm not being nasty, but it's true, they are in the shit financially.
AIBU? Was I was rude, or are they just being overly sensitive? I think they just need to grow thicker skins. I think DB is being ridiculous, but I'm also prepared to be proven wrong.