My Dreadful Darling 

This one comes with a real trigger stack, so let's talk through it. The bullying is extensive and escalates well beyond verbal — Dread's "pranks" include leaving Reverie handcuffed to a flagpole overnight in a blizzard until she's blue and hypothermic, staging a fake cop arrest while she's having a panic attack, placing a butchered dummy in her room to trigger her trauma around her serial killer father, and burying her alive in a grave he dug on her birthday. That's physical abuse and captivity, not just mean-boy energy. There is significant emotional, psychological, and verbal abuse throughout — four years of sustained torment and manipulation/gaslighting, including the use of intimate photos and recordings against her. The dubcon is real and consistent: Dread regularly pushes past a "no," and there is a specific scene where he presents a coercive ultimatum (have sex with him or he'll drown her, weaponising her known fear of water) — several reviewers classify this as non-con rather than dubcon, so both are flagged. Stalking is central to the premise — he follows her to the same university specifically to torment her. The serial killer subplot brings murder, violence, and gore (a copycat killer is active throughout). Both MCs carry heavy trauma/PTSD from childhood — Reverie from growing up with a serial killer father, Dread from witnessing his mother's murder at age 8. There are voyeurism elements including secret photos and sex recordings. The stockholm syndrome dynamic is acknowledged by readers. The overarching relationship is toxic by design. Ends on a cliffhanger — book two is already available.