Armaan isn't realizing himself. he needs sometime to understand his feelings. He must be thinking that being so handsome, rich, the heartbeat of millions of girls & after belonging to a sophisticated society , how can i really fall for an ordinary, ugly middleclass girl? Its his ego which resists him to realize that true feelings. Armaan is consoling himself by saying that he is just playing a game to save Gulmohar. But the fact is that day by day,he is unknowingly falling very deeply in love with Jassi. So when AS is talking to raj about wooing jassi, he isn't feeling anything for her but whenever he's making love with jassi , his all feelings are coming straight from his heart and getting overpowered on his mean planning which unfortunately armaan is thinking that he's only acting so nicely. Actually he isn't acting at all .Anybody can see then that madness of true love in his eyes, expressions. What a great acting! It's very difficult to portray 2 different moods in same sequence but which our Apu is doing so nicely. Really great!