Please no. Others have covered why.
If it’s done in a reasonable way, I’d be fine with this? But I think it depends a lot on execution.
So, e.g., “main character makes a major decision abhorent to RO, prompting break up” would probably be fine, if the RO’s opinions were clearly telegraphed beforehand. “Main character has a series of small interactions that put the RO off, prompting at least a talk, maybe a breakup”: I’d probably also be okay with this, depending on how it’s written. “Main character hits 80% on sarcastic/sincere meter, prompting sudden breakup”: probably not great.
(I talked about basically this earlier in the other thread.)