I'm totally confused as to whether BB is or is not Cheung's daughter.
Did SS intentionally lie to BB that she cannot be Cheung's daughter? Google says father blood type A+ mother blood B or AB can have a blood type B child. So it is possibly for BB to be Cheung's daughter.
And the last scene -- were BB and SS just playacting to trick Lai Kuen into think that BB and SS are in discord because BB is not willing to help SS see revenge against Cheung?
SS looks so youthful here, like a young man in his 20s.