6 months clause?

but, what i noticed was when arnav first said about marriage, he didn't include the 6 months clause at all.. he was waiting for khushi's reaction and when she said "what?" with shocking expression and after this only he added 6 months clause.. this was the convo

Arnav: "u will have to marry me now" and waited for her reaction.. 

Khushi was taken back and asked "what? what is it that u r talking?"

then only he said u heard it right and then, u will have to marry me for 6 months..

We know that CV's added this later but, what i feel is, as per d convo, arnav thought about it at that moment based on her reaction and added this clause.. don't u feel so? he was the one who told anjali during lavanya break-up that "when i am not sure of the feelings, how can i give a bigger commitment" and now he is now ready to give that commitment to khushi but the irony is he feels that khushi is not willing to do that..