I am moving area in a few weeks and my friend and I decided to go to a Spa together for a treatment. I had a voucher from some months ago for my birthday and she also wanted a treatment so we decided to go together and make a morning of it!
My friend very kindly offered to pay extra for me to have a more expensive treatment but I declined because I really only wanted a manicure (she booked the same) and so instead, she said she would buy me lunch after the Spa as a goodbye present.
I accepted and thought she was very kind for offering so off we went to a restaurant after the treatment. We did have starters and coffee as well as a main so I fully intended to put £10 towards my lunch as I didn't want to take the mickey but when it came to bill time (£50) she just said "lets split the bill" 
Now I know it is not the end of the world but I had just sold a couple of old toys on ebay and so had a little money in my purse to pay for the ingredients for my daughters birthday cake. I had to use this to pay my half and my friend even commented on clever I was to 'remember cash'.
Then I had no money left to get the cake bits and I came home really angry. I would never ever have gone out to lunch with that money if she hadn't offered to pay. I sound like a money grabbing cow but I had to stay in for 2 days running to wait for people to collect the items sold so I had money for the cake....should I have said something??
No of course not. I would have sounded so rude but oh what a waste of my money.