You and your girlfriend Katie have been dating for 2 months, everything is going well except for 1 thing: 'Girl math'. She only uses girl math instead of normal math like when 5% discount on a £50 shirt equals to £47,50. While girl math is when there is a buy one get one free sale, we will always take the free part. And this annoys you alot. You tried explaining that the girl math thing is wrong, but she wont admit it.

Katie: How are you this dumb not to take the free part?!