I’m not sure where you’ve heard this logic buT i hear that being said alot about those who cheat, that if a man can cheat on his spouse wiht a woman, what makes that woman think SHE won’t be cheated on once hes left his wife for her.
However it’s not the same when it comes to a divorce. I think the further the relationship was (a baat pakki ro engagement vs a nikkah but no rukhsati vs living together but no kids vs having kids), the more complicated and messy it is.