Flawed leads are becoming increasingly common in fiction. I know some readers still struggle to read books featuring main characters who are less-than-likeable. The occasional quirk is usually okay, or even some arrogance or a tinge of psychopathy but it’s still often harder for many to engage and identify with a character who we might not like.
Bethany Reston might be such a character for some because she tells us outright that she’s having an affair. Indeed it’s on the backcover blurb. So we know that from the start.