
Did you re-read chapter 160? Things would be much clearer if you did. In chapter 160 he told Shan that he didn’t want Shan to like him more and more. In another chapter, Tian lent Shan his jacket. In chapter 307, we found out that Tian secretly slipped a note inside the jacket which says “I don’t want you to like me more and more - that was a lie.” The note is a reference to what he said in chap 160 and was meant for Mo to see.
I have no idea why this note confuses so many people even though some readers have pointed to chapter 160 as explanation lol.

The piece of paper in chapter 160 has nothing to do with the piece of paper left in the jacket. That note from chapter 160 has already been revealed in a later chapter ( the same one when She Li showed up at Mo Guan Shan's house). That note He Tian wanted Mo Guan Shan to keep without reading was a joke ( Mo Guan Shan opened it and read it ( It said: Idiot, I knew you would secretly open it. Come make me dinner'. Mo threw that note in the trash.
The importance of chapter 160 is because it has the convo where He Tian delivered the line 'I didn't want you to like me more and more'.
Fast forward we get the scene where He Tian forces Mo Guan Shan to wear his jacket... he probably slip the confession note at some time before giving the jacket to Mo.
Wait in ch160 he was meant to pass that onto someone - was it not intended for Mo? Please help me out with context! Σ(っ°Д °;)っ