It's clear to me too. The reaction he had to that love question was just too much to be nothing. The guy never mentioned anyone in particular but Mo denied it so hard as if he has something to hide or feel ashamed of. He lashed out at He Tian (who was being nice) because he feels awkward about it and thinks by getting He Tian to go away he won't have to deal with the confusing feelings. Mo was pretty chill-as chill as he can get anyway until that conversation happened. It's just too big of a coincidence. The naysayers just don't ship them. Not as they actually are at least.
:') ah beautiful.
Mo is in love and aint nobody can tell me otherwise