What does "BMS" stand for on Instagram?

"BMS" is an acronym for "broke my scale" on various social networking sites like Instagram where individuals post photos. It is typically found below images, and implies that the person posting the comment finds the person in the photograph very attractive.

"BMS" is a reference to the subjective and somewhat arbitrary 10-point scale that people sometimes employ to rate other people's attractiveness, the highest rating being a 10 out of 10. To say that someone breaks the scale means that they go beyond 10 out of 10 and have therefore "broken the scale" of attractiveness, far exceeding normal beauty.