It IS noona's ex, but there was some weird sexual tension between them when they first met, they've been keeping in contact and now they're both going off to Los Angeles together. They're both heartbroken too. His crybaby/crazy personality is actually really similar to Subin, Hyunwoo even made some comparisons like when he ran off into the ocean just now and when Hyunwoo was talking during one of the interviews and said they got into some interactions. The way noona wasn't going to save him, but Hyunwoo ran to save him makes me think he'll fall for the guy's antics more in the future, which might make the guy fall for Hyunwoo and decide he will be good to take care of him.
Nam hyunwoo came back so strong I can't help cheering on him aargh gosh!!