Lot is being talked about Farhan being from NY , Zoya's friend and creating jealousy in Asad's mind Zoya . However, my view is Farhan entry is more suitable for the Ayan Humeira love angle.
Though Ayan is worried etc for Humeira and seems to be fallign in love, but it will definitely require a major push to come forward and say I LOVE YOU to humeira. Remember - he is the one who wished not to fall in love during meteor shower.
This will also mirror Tanveer in the Asad - Zoya love story and lot is being talked about parallel tracks in the context of QH. If we want to take this a way forward, Humeira, may start calling him Vikram and keeps on asking why Vikram do not recognise her etc...putting further twist.
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