He would probably be annoyed at the boys but he wouldn't show it. He would finally have enough of the teasing and jokes to actually go and ask if you did. When you said you did he confessed that he liked you as well.
When the boys told him you liked him he couldn't wipe the smile off his face because he was so happy. When he went up to you the next day, he asked you on a date, he might of also told you that a little birdie told him you liked him.
He wouldn't believe them at first. He would think they were just teasing him because he likes you. He probably wouldn't go up to you right away, the boys would have to find an excuse to get you you two alone so he could ask you on a date.
He would just laugh it off in. He wouldn't know what to do with himself but, once he found out he went straight up to you and confronted you nervously.
He would be just like Kihyun just a little more extra. He would be able to keep himself together when he was around you. He always ask himself why you liked him. You would be the one to ask him out because he was too nervous.
This cute bean would be ecstatic when the boys told him. He wouldn't be able to hold himself together. When he went up to you the next day, he made sure to use his ageyo, (which you love) and he asked you on a date.
Changkyun would know if he should ask you out right away or wait. When the boys told him he was happy, but he wanted some time to compose himself before asking you on a date.