爸爸愛媽媽。

What a wholesome sentence, lol

Because fuqin and muqin mean a father and a mother, not dad and mom. I think that when you say 爸爸爱妈妈 it implies you are talking about your parents and therefore it sounds better to say dad loves mom rather than "father loves mother". That's just my opinion.

Of course la... so that you're in this world

Why 父親愛母親 is wrong？

It doesn't bloody matter where there stupid names go