"nothing she did is a problem" The husband told her he loves her brother. He said NO when she proposed the marriage. She knew from the start and did not even inform her brother who she was going to marry despite knowing their history. Of course the husband shouldn't have agreed, but what did she thought his intention was in marrying her? To get her brother obviously. All three are at fault here.
She's not at fault at all nothing she did is objectively wrong just say you hate women because to blame her for being delusional for thinking she could make him fall for her and being cheated on is crazy. Nothing she did gives her fault in the situation. The brother and husband were broken up when she started pursuing him. The husband chose to say Yes so that he could destroy the siblings relationship. The brother knew he was in a relationship with his sister when he started sleeping with him again. The only one at fault for the situation is the husband and brother
Seriously I don't know why there are readers siding with her (not siding with what ml did, too) like did we read the same manhwa or what hahaha. Then accused us of being hateful towards a woman when all we did is point out what she obviously did wrong. And reading their replies made me think "oh they're dumb and not understanding each characters"

because I know bisexual men exist i don't think the sister is wrong for being with a man who sleeps with other men or for wanting to still be with someone whos in love with someone else I read enough manga where delusional mcs get the happy ending but unfortunate for her she's not the mc. both the husband and brother are irredeemable trash tho