I'm aware this is going to sound incredibly petty.
Me, DP and his mum are all on Tesco Mobile. The bill is paid out of our joint account every month, including DP's mum's. This is because DP has paid for this for years as it started when he lived with her, and it's carried on. He puts more money in the joint acc so I am not personally paying for it.
A couple of months ago I realised we can get Tesco Clubcard points on this, so I checked the account. We pay about £50 a month for all the bills so I thought we may as well get those 50 points. There was another account number listed on there, so I changed it to ours (mine and DP's card). The other number was his mum's, presumably inputted when he lived there (about two years ago).
DP's mum has now messaged him asking why she isn't getting the points, as she's checked her statement and they aren't there. DP said I've changed it to ours, and she said I am selfish and it's always been her card that gets the points as she likes to save them up. Well, so do we. I think because we are paying for it, we should be getting the points on our card and she's being cheeky. She has more money than us (as she has no mortgage or rent), yet DP continues to pay her bill out of kindness and all she's worried about is points. AIBU?