Is Karthik started losing int on suman?

after yesterday episode i felt that he started losing int on suman,i thought he is very strong character and will love suman to the core.....but he started neglecting her

No, Karthik has not lost interest in Suman. He wanted Suman but Suman refused because she is such mahaan. But he is always looking at her and having eyelocks with her. Even today, when he was helping Nandu after she fell, he glanced at Sumi.

i think so he is observing Sumi's reaction, ..which he knows that Sumi doesn't like it., but is not ready to accept it..

he could have neglected to put the necklace.....im sure nandu seduce him with in 2 days

Well, Karthik is helpless and he knows Suman is crying her heart out within her. He is only trying to get her reaction to this whole thing and get the truth. Lets see what happens.