my theory: Ye Jia Hui's father is Ye Nian Fang, and Prof Ji had an affair w/ his mom (or something w/ his mom) but i think it's just a misunderstanding

but i still can't think what his intentions are towards He Dun

I think he's using her to get to the professor. He already should be in jail for the patient tampering and spying alone. In the previews to the next episodes, I think (I don't understand Mandarin) he's going to "confess" to her about wanting her to be his gf. ?

Im pretty sure that the guys mum was the profs patient but he misunderstood that they were having an affair which is why he got pissed when prof said he didnt love anyone?