What happens if it is your parents' opinion as opposed to your partner/spouse? Who do you listen to? What do you say to the other party?

Is it really true that if you love a person, it would not matter what your parents or the other party's parents say? But do we not have an obligation to our parents because they are afterall our parents?

What happens if your partner is asking for something which is something perfectly reasonable and right but the parents are against it? Or vice versa, where the parents are asking for something and your partner thinks otherwise? What then?

Our parents did brought us up and did provide for us, food, shelter, education. Without them, we would not be what we are today.
As humans, we need someone to love, well, most of us. And if that someone comes along, you know that you would do anything for the person. So what happens when 2 worlds collide?
Hmmm...