While I don't ship them romantically, I find their relationship really interesting in both the novel and in the drama. There seems to be an amount of mutual respect and understanding of each other, although they are somewhat at odds (especially in S1) because of Xiaoyao.
The scene between Jingye and Jing when they are talking about the Chenrong army is a nice short one highlighting this. And I find in Ep 6 when he is talking to his astral fox that he will let Xiaoyao choose this time who she wants to be with showing his coming to terms with XL being a viable partner for her.