Tinder Rule of Two
This term is a universal rule of probability. The rule states that whenever there is a picture on a dating app that contains two girls, with one of them being significantly more attractive than the other, the person whose profile you're swiping is the less attractive of the two.
When I saw Isabella pictures on Tinder I got excited when I thought she was the hot girl on the right....turns out I fell victim to the Tinder Rule of Two.