Responses
Since MC is trying to hide his identity from ML, he has probably given ML a fake name while pretending to be an anonymous fanboy. (I don't recall his fake name being addressed.)
As for ML's joining the fan group, MC initially thinks it's a fan pretending to be ML but he soon realises that ML is the real deal.

Did he really date someone without knowing their name? Or i just missed where he told his fake name?