Takes notes from Shield Hero(dude has trust issues, buys a beast-child slave who grows up overnight), Level 2 Cheat Slow Life(he goes from zero to Gos in one fight), and every other "kicked out of the Hero's party" story.
I'll be reading this because these guys are extra shitty and I'm probably gonna bust a nut when karma bitch smacks them, but I know going in this is not going to be a particularly unique or thought provoking story.
On that note, what grabs me with this particular premise is that while the "Hero's Party" are often(not always) assholes in HOW they kick the MC out, they're reasoning is often(again, not always) valid. At least in the stories I personally read, the MC often is a straight up liability as the battles get harder, and it's not until after they leave that they find some kind of cheat skill/item.
But this time, there's no excusing the adultery. So I'm looking forward to his fiance's regret more than anything.
Edit: And after reading a few chapters of the novel things take another(and not entirely shocking) turn. So I'll only be looking for the Hero to get his due and hope for the best for everyone else.