Hear me out....
I don't think Jiheon is really smiling when Wooju was kidnapped or he really following Wooju with camera. I think it's just a side effect of the drug he took. On previous chapter he had a doubt on Jiheon which might have been reflected on his dreams then his hallucinations when he woke up











It's nosebleed. I think.
Not some heroic act of self control like biting his own arm. It's very evident that his so called self control has already disappeared down the drain ( ̄へ ̄)