He can see that his request made Wei Ying hurt, but he didn't understand the complexity of his grief. It's correct that the one he loves had died in the buried mounds.

"No. It's you I want. It's this body of yours that I wasn't able to said good-bye properly. When you were gone, I went searching for you. I cannot find your body."

Without saying another word, he tilts his head and closes the distance between them to give him a crushing desperate kiss to release whatever grief is still in his heart.