@Just Love To Read in novel i believe, niannan did not let them tell the truth to gu yansheng because niannan don't want yansheng to have a feeling for him just because he's the one who saved him.
@Nikolai then how can mc think that ml would love him if he won't tell him truth. How can he expect that then. like some miracle would happen & ml would get to know the truth. I'm not in support of ml but still they can solve this issue with proper convo.