@Lily he didn't specifically state that he liked him. He said he was conflicted with how he felt towards him. Dont forget he also said he gradually saw him as a younger brother in the previous chapter so probably that's has an effect on how he's thinking now. Plus Wooseo was said to be a senior which is about 17-19 years didn't specifically say when. Also you can see that he himself is also concerned about the situation or that's just me 

If you dont let me suck your di** I'm gonna kill myself
TAKE YOUR PANTS OFF RIGHT NOW 
TAKE YOUR PANTS OFF RIGHT NOW 