Girl, you need to change your attitude, don’t be cruel😢

This is a short horror comedy episode (motion comic) from the Singaporean series Silent Horror by creators DarkBox & K.S., distributed on the app ComicVid.
The story is a classic “misunderstanding turned nightmare” gag with a dark twist:

A short, overly enthusiastic boy repeatedly tries to confess his love to a tall, beautiful high-school girl by giving her a Valentine-style heart card (and later flowers).
The girl is clearly uncomfortable and repeatedly rejects him (sweating, looking annoyed).
Her friends watch from the classroom window and laugh at how “cute” the scene is, teasing her.
The boy keeps coming back, more desperate each time.
Eventually the girl snaps. In a fit of rage (or madness), she brutally murders the boy off-screen (implied by the blood splatter when he offers flowers).
The friends, still watching from the window, suddenly realize what just happened and scream in horror.
Cut to the girl and her two friends now all wearing the exact same creepy, wide-eyed, unnatural grin (the signature “Silent Horror” face), implying she has completely lost it and possibly killed her friends too, or corrupted them into the same psychotic state.

The punchline/horror reveal is that the “cute romantic comedy” the friends were laughing at was actually the prelude to a psychotic breakdown and murder(s). The series is famous for these sudden tone shifts from slice-of-life/rom-com setups into absurd, grotesque horror, all delivered completely silently (no dialogue, only visuals and sound effects).