I went to the pub last night with a close friend. We were there from about 7 until about 11. Had 5 drinks, so about one every hour with water in between. She bought all the drinks as I had paid for our food. I was drinking rum and coke. Every time she got me one, she asked if I wanted a single or double, and I said single. She went outside to take a phonecall so I went to the bar to get some more water. Barman said 'two double rum and cokes again?'. After asking it turned out she'd been buying me doubles all night when I asked for singles. I had even made a comment earlier that the rum was super strong but she brushed it off. When I asked her she said she thought I was asking for singles because I felt bad about the cost so got me 'sneaky doubles'.
AIBU to think this wasn't OK?