Hamza's behaviour in this episode - particularly with Rumi - dint seem like he was faking it..infact it never felt like he was faking it with Rumi - their relationship has grown a lot from their first interaction - more like a natural progression. When he came back home..he seemed to be very worried for Rumi.
On the contrary whatever he felt for Hamna feels more like some irrational and erratic obsession than love..ofcourse its super creepy that you marry sister of the one you loved..just for sadistic pleasure..so I can totally understand Azeem and his plain disgust towards Hamza ..I was literally lolling when he was shaking his head in the hospital.
My point is that whatever Hamza's "revenge" plan was dint make any sense..and now it will continue to not make sense even further..because he is already in love with Rumi.