Responses

Yes, he's in love with his noona (older cousin (not sure if blood related), the woman who just got married). Apparently Yuri saw his ex teacher bawling his eyes out crying during the wedding so he thinks the teacher was in love with his noona or something like an ex boyfriend of her. That's why Yuri's asking him so many questions, cause it's related to the person he loves (his noona).
I think I forgot some details form the previous story. What exactly is the relationship between yuri and haejoo-noona? Are they blood-related? Does yuri have a crush on her? I'm a bit confused