I don't mind cheating or assholish ROs as long as:
1. They receive consequences.
2. The author doesn't shove them in your face all the time.
A terrible example is that ex of yours (Seven I think was their name) in that music reality show game. They're assholes who hate you for no reason, no matter what option you pick. even if you didn't vote them out of the band. Of course, the game keeps shoving this character in your face constantly.
From the games that I remember there are very few ROs who can cheat on you, all I remember is that princess from War of the West and your childhood friend in When Life Gives You Lemons (you can choose whether or not she cheated on you during a high school party). And of course Can't Stop Your Love From Dying. This WiP was probably made by a fangirl who in a hypothetical scenario wouldn’t mind being cheated on by her popular musician husband because, "uhh, it’s the industry’s culture," and "he’s famous, so he can’t settle down."
Characters that hate you for literally no reason **** me off so ****ing much. Examples: Morgan from Wayhaven book 1, that character (forgot the name) from A Mage Reborn: Book Two, Blane from When Twilight Strikes, etc. (When Twilight Strikes infuriates me for a lot of other reasons) Safe to say I don’t like assholish ROs at all, not even those "red flag" characters. The closest RO I like that could be considered a red flag is Junko from SOH and your ex-lover in that John Wick-like IF. I don’t know, they just **** me off. Unfortunately, few games let you kill annoying ROs, so you’re stuck with those assholish characters forever.
Also not a fan when a game makes the MC suffer but doesn’t let us take revenge for it. I remember there was a game set in ancient Rome where a Roman general killed your family, but you didn’t get the chance to kill him. You could even romance him??? I don’t know if the MC ever gets to kill him since I didn’t keep up with the updates after that point.