DP regulary gives money to his sister, she isn't wealthy and she has a daughter of her own and is a single parent. I've known he's been doing this for a long time but we only started to living together 6 months ago and up until this I thought his money his choice. However in the last 3 months he's given her about £2500 and according to him this is because her boiler broke and needed repairing and to buy her laptop because she needs a computer and internet access as shes started to train to become a social worker.
Whenever I have tried to talk to him about it he becomes really defensive and sensationalist, saying things like what do you me to do sit here whilst my sister and niece shiver in their own home. Another thing is that his dad was abusive and his mother was an alcoholic and his sister who is older did look after him and he claims that if it wasn't for her he wouldn't have any money anyway and that she deserves some of it because she looked after him and made sure he went to and did well at school. We are thinking about TTC and so I think we should start saving, AIBU to want him to stop