Mushed has an understandable boss and a wonderful mother and Zhong has... almost jeopardized her entire career/life, and a questionable/controlling parent whom she is fighting for this particular relationship but... Mushen is tired. Of what? I don’t understand.
I think she felt like having to tip-toe in this relationship for years, exactly because she knows Zhong could have lost everything in an instant.
It may not have been the best moment to tell her about 'feeling tired', but that's how it is when you are closed to your limits.
Girl, you cute.