I don't think they were a couple. Just one sided from her, and that's make all the photo thing even worse
I am pretty sure they were not a couple... She was just openly crushing on him... I mean they got like 2-3 scenes together and they never called each other in an intimate way. She was just pissed that her "hard work" to get him got to waste because of a guy... Kinda hurt her pride too I guess and they crazy bitch decided to take her "revenge".
Btw could you please share the title of harada's story with a similar plot? I would love to read it! (=γ»Ογ»=)
this reminds me of that one harada book... just less fucked up.
side note, the gf: i completely understand wanting revenge on someone who cheated on you but she deadass said that she wanted to be with him after that like... i know you didn't mean for everything to get out of proportion but girl... why would you still be interested in him. if i caught my bf doing intimate things with another guy i would reveal to the world he's a cheater and then NOT try to get back with him or belittle the person he cheated on me with.