Parents may deceive other people, but not their own children. Persevere with your love. A bad marriage need not remain bad forever. Generations of unhappiness hound the human family. We pass such unhappiness from father to son and mother to daughter - and from father to daughter and mother to son.
Somebody simply has to break the cycle.
They never saw much love between their own father and mother. If they do learn later from a stepmother or step-father, their own husband or wife, or from a constant struggle to fulfill the teaching of God's Word, the change will require great effort. Such people have to work harder at having an adult, trusting relationship. To put it another way, how our parents treated one another is not unrelated to our own situation. The Bible is filled with advice about relationships.