I stayed at a friends house last night and we nipped to the shops and we bought some food to share. She claims she lost her debit card but she still picked up a few bits for herself.
Unloading shopping and I start to separate it and she quickly says no you pay for it together and I'll pay you back. Fine I don't mind buying snacks but why should I fork out for your household items 
We then bought takeaway .. which when I came to paying she stayed quiet and so I paid on my card ... we shared it with her housemate which I like but said no word of thanks.
We went out today (planned) and I had to again buy her 2 drinks and food as I ordered for myself and felt rude her sitting there not having anything.
This is on top of all the money I've lent her this month.
Total of money is around £180. I HATE asking for money back and some of the things are like £5, £15 etc so I feel petty asking for it back.