Where did it go so wrong?? The seemed so hapy and in love

I forget which chapter(s), but there was a part where Minho mumbled something about what Woojin said the first time they had sex being a lie and maybe in that same chapter it showed him thinking about seeing Woojin smiling at some guy (not Taehwan from the looks of it). So my guess; is Minho the idiot just misunderstood something with his jealous/secretly insecure ass who was probably lowkey scared about opening up to someone for the first time and started to treat Woojin like trash because of it instead of communicating properly.