Om being an illegitimate child

I was wondering why Shivaay didn't remember the revelation about Om being illegitimate during Tej's Naam Khoon Khandaan rant? Didn't he feel something amiss? Tej wouldn't be stressing so much about bloodlines and family honour if Om's birth had a murky past? He rejected that match for Priyanka - Dev? - for this very reason. I know he is the last person to talk about family honour given that he openly had an affair with Svetlana but he is shrewd enough to ensure there are no children who have a claim to the Oberoi wealth.

So why isn't this more of an issue to Shivaay? His reaction seemed fairly mellow considering his obsession with NKK and his love for Om. Or was this just a filler track that chose to serve no purpose cause despite SSO tearfully twisting Annika's arm into signing the divorce papers, she didn't leave the Oberoi house - as I had wanted her to, from the very first day of the forced marriage.

I didn't watch today's episode. Maybe there was something related to this shown today?