How did Durga get to know about Raime-Rajnath?

I am following this show since a while, however, I think I missed the episode where Durga gets to know about the affair between Raima & Rajnath. Can someone please elaborate on this track?

I don't remember properly but I think it came out when durga set CCTVs in raima's house and there she came to know abt RajMa!

lol.. I think I have missed more than I imagined I have! CCTV in Raima house.. when did that happen? I remember Akash putting in cameras at the college principal's house(dont remember his name now - the one who was exposed in his own party).

I too had skipped some episodes but I somehow remember akaash coming as a electrician into raima's house and setting cameras.

How she learnt about it is not elaborated. May be in those 2 years.