Originally, I was contemplating limiting it to just the most egregious examples in BL (Boys' Love), but I've decided to broaden the scope to include any romantic interests.

This question came to mind as I've been perusing numerous comments regarding the character Jinx. Just to clarify, I haven't delved into that series myself, so I'm unable to offer any informed opinions on it. However, it sparked the idea to inquire: who stands out as the most detestable, toxic love interest you've encountered?

Furthermore, I'm specifically referring to characters intended to be taken seriously as romantic partners. For instance, I'm excluding stories like Killing Stalking or Placebo, which aren't typically viewed as conventional romances.

For me, the worst love interest I've ever come across in any narrative undoubtedly goes to Richard Tarten from plnkgame.com the Passion sequel. This character's demeanor is despicable, and the romantic dynamic left me thoroughly displeased. If anyone else has explored those novels, I believe many would concur.

most of the toxicity you see in manga is so over the top you couldn't reasonably consider that person a partner; it would be a police matter the first time it happened.
it's possible that a prospective partner can be compromised and not act appropriately
or lack understanding/be naive; it's up to you to decide if they're a slow learner or not putting effort in
or if the circumstances for them being compromised will appear again, and at what frequency.

In my dating game(I'm getting close to 50) everyone is damaged goods or a broken toy.
I'd been friends with someone(prospect) for more than a year and everything was good, until I was at a dinner party and they started hitting me. I'd probably been annoying them because I tend to monopolize social situations and being a big mouth at the party they're hosting is probably rude but not worthy of such a reaction.
I get really worried about stuff like that.
Where someone is really nice for extended periods of time until they're under duress and then they're incompatible with you.
Being in love kind of turns your brain off.
I try and avoid that until I'm sure.