I am happy to accept IABU.
SIL asked to borrow money for her wedding. To pay for the ceremony she couldn't otherwise afford, we lent her and BIL £700. No payment plan metioned (I know).
She also borrowed money from MIL. Now she regularly borrows/borrowed money from her mum. He mum isn't over the moon about it but is happy when she's paid back, but SIL takes her time. So after speaking to SIL her plan is to pay us back after paying her mum back because her mum is paying interest on the money she's lent (credit cards etc) . We said "fine". Point being we forgot how "casual" she is about paying her mum back. So 4 months on SIL is posting pics of her latest beauty treatments, days away, shopping trips and it's bugging me! I don't think I could say a word. But I can't afford a hair cut. Our fridge broke down and we've had to buy one on credit because we have no savings. They're driving a brand new car, wearing shiny new clothes, and it is grinding on me. I know IABU because i didn't set any terms but tbh my AIBU is more along the line of so you know people like this? People who can shamelessly lend money and flash their life style? Am I alone?