Your compare the wrong thing here: 1) Xiao Feng and Lou Xuan are not Father and Daughter, they just DIFFERENT in AGE. And yes I agree with you that he cannot surpass himself to be with her, but compare him to her as her dad, wrong!!
2) Yes, I agree, Xiao Long Nu and Yang Guo both think teacher and student relationship is OK that why they together, agree. But you cannot bring the DAD and Daughter relationship compare. Xiao Feng and Lou Xuan are not blood related. Honestly, I think they can make it, so what of a big gap of age different. And you right, it is him that cannot tollerate such a thing.
And Yes, incest is wrong, but Xiao Feng and Lou Xuan are not consider incest.
My question is: You think he actually love her?
What everybody thinks? Do you think he actually love her?
NO offend OK Kidd, just discuss opinion with you.