Re: infidelity, I'm v. hypocritical. In a pairing, I almost always have a character I favor. So Draco being unfaithful to Harry = a-okay, while Harry being unfaithful to Harry = not okay.

It wouldn't stop me from reading though. I just skim/skip the Harry infidelity scenes.

In romances, I'm fine with physical infidelity but not emotional infidelity.
In the Administration series, I'm not bothered at all by Toreth fucking people left, right and center. Because it's (almost pathetically) obvious that Warrick is the one he's emotionally invested in.

Warrick deliberately cheated on Toreth once to hurt him--and I 'forgive' him because I understand his motivations in hurting Toreth.