One thing I like in this series is how it depicts teenagers realistically, as socially awkward people who speak before they think or else keep in their thoughts what they should say aloud. It's refreshing how they're not over-rational (the two protags excluded as they have adult mindsets). If the glasses guy were an adult, he'd come clear and say "No, please don't lose on purpose", but because teens are often looking for shortcuts that avoid facing up to facts, he didn't.
Also, why do I keep thinking that Da-ae will finally get an injury that will prevent her from becoming a model, and Han-eol will also get in some sort of accident while trying to lose on purpose, and involving that kid from the scuffle before? It's like they have absorbed the bad luck of their siblings instead, and they're the one who will die if they get married.