It's the idea that if you love your husband or wife but you still are attracted to other people, there's something wrong with you, there's something wrong with your marriage, something wrong with your partner.
남편이나 아내를 사랑하지만 다른 사람들에게도 끌린다면 무언가 본인에게 문제가 있거나 결혼에 문제가 있거나 배우자에게 문제가 있다는 생각이 잘못된 겁니다.