My theory
Like Payal said he does not want to look bad in front of Prarthana.
The mostly likely reason is since Prarthana was leaving pretty quickly he wanted to stall her from reaching Randhawa house so BM-TS team can ensure Shivansh starts to believe in the lies . Or both of them most likely .
Payal will be able to hold back Prarthana longer and buddhi ladki obviously believes him
Thieves don’t honors and biggest thief is Raunak himself.
Agreed. I feel he got scared the moment Prart said, this is the last time we’re standing like this. I won’t talk to you ever again.. To protect his image and make sure he doesn’t lose her forever, v conveniently he shifted all the blame on Payal and gadhi Prart actually believed it
4