I had this theory that that the paintings in the Korludag mansion at the end of the hall way right next to the room where Cesur was staying "one of a blond boy" and "one of brunette girl" might be of Cesur and Suhan painted by Cesur's dad. So maybe Suhan and Cesur did know each other when they were kids. But it seems that things went down hill between the two papas before the kids were born. The timeline is all messed up anyway because it's too early in the story line I guess...
Also I imagine that the Sirin and kemal's weeding will take place in the 6th episode and for sure Suhan and Cesur will be the witnesses and he will make another one of his weird marriages comments to her
After finishing the episode i'm absolutely sure Kemal knows that it's Emir's set up. He must have gone to his house and saw that Emir and Nihan were out. When Nihan called him she said that she was at home and couldn't meet him because Emir was there. Kemal was probably outside the company and knew that she was lying to him.
Besides, after seeing and recognizing Asu's bag there's no way he is going back to her unless he has a plan.
Emir is a total psycho, I felt so sorry for Nihan. She really has no idea of what she's doing. Thank God she has Kemal.
I don't think that Kemal will know so soon that Asur is Emir's sibling, but the fact that he started be suspicious about her is very positive.
As for Nihan's and Kemal's scenes, the only thing I have to say is that their chemistry is bomb. I need more romantic scenes between them. Neslihan and Burak nailed it.