My brother has asked to borrow money. I dont have money, now he has asked me to borrow money from the bank for him. I have done this for him before but he never paid and I had to pay off his loan. IBut this time I cant afford to pay the loan if he doesn’t pay, as I am the only 1 working in my household at the moment.Is it a sin if I say no, i have mentioned the previous time to him but he is insistent that he will pay this time and makes no mention of the previous loan. He has also asked me to pay for flights previously and hasn’t paid.