[RCF]

Lets see what's in store for them. 

Have you noticed when he said "Everything was fine until they were friends, when love came everything turns upside down'

Its one of Hint

Yes that's his justification for her question on why he was being unfair to her and its perfectly apt. Though he should allow her to pursue her own wishes as their marriage is still a contract between them, him trying to show his love is not wrong. It should technically stop Nikita and she should make sure if he is truthful but she is already attracted to Tharun by then and she couldn't see the love from Jay. 
Irrespective of whether she could see Jay's love for her or not, My point is she loves him and not yet realized. When she first kissed Tharun on terrace, she was broken, she felt like she betrayed, she wanted solace in the arms of Jay. Only a person who feels she cheated will react that way, if it was just a marriage on paper why would she feel that way? Her saying that Jay slept with Anjali so I will sleep with Tharun is OK for argument sake but true inner feelings won't lie to them, they will reveal where her heart stands at the end. 

~RCF