What? Does Cheng already know that Wowo is his? What will be Ci Nian's reaction?

Of course! Didn't you see Cheng do the DNA test on Wo Wo? Also the Doctor confirmed it over the phone too. So our man Cheng knows he is the Father. Ci Nian won't ever tell him though. He probably drag it to his grave, like he won't admit sh't. That's why Cheng did the DNA test.

OMG!!!!!!