No matter how vampish or dominating and controlling; mallika has been shown to truly love armaan from the bottom of her heart and I really pity her coz she has grown up thinking of him as her future, if she was suspicious of her fianc a bit too much I must add she was give every reason to be so, Mr Suri never has taken pains to mend things, no doubt it is tough for him too as its very difficult to marry someone you don't love but I feel its too late for him to ditch her.
Jassi on the other hand never really loved Purab infact since he has gone she is busy mopping tears for her looks not for him, and she even managed to get her boss to give her a shoulder to cry on (she may think all the time armaan should be with Mallika but actions speak louder than words) and no matter how innocently a woman thinks the responsibility for a breakup does lie on her also at least partially, (and Jassi better realize that )
and Armaan i hope he clears his emotions so the hurt his actions are causing stop soon