This kind of framing is quite negative and potentially harmful. It's important to approach relationships with understanding and acceptance of each other's pasts without using such derogatory terms.
Rather than focusing on what might have been in the past, it's better to look at the positive aspects of your relationship now. If you love her, her past should be secondary. For example, focus on the memories you create together now, like traveling to new places or sharing hobbies.
I don't know the reason for such stories. It might be part of some dark and unethical fictional genre or just a random, offensive idea someone came up with. Such themes are best avoided as they have no positive value.
Rather than focusing on such offensive concepts, we could look at stories about loving, supportive and equal partnerships between spouses. For example, stories where couples support each other's dreams and grow together.
Well, some of the themes could be the exploration of forbidden desires, the challenge of societal norms, and the internal conflict of the characters involved.
These stories can make society more cynical about marriage. People might start to doubt the institution of marriage as a whole when they hear so many stories of cheating wives. It can lead to less trust in the idea that a marriage should be a lifelong commitment.