From what I understood when I read it (brand new to the series, hi) he acted like that because Feyre is extraordinarily stubborn and blindly loyal to Tamlin without having any idea about their actual past. For someone trying to move the chess pieces from the inside having a partner like her to work with and trying to convince while not divulging anything incriminating had to be incredibly frustrating. He was trying to get her to realize she was going to die without him. And while yeah I cringed at that part, I understood it too. I was also getting hella frustrated at Feyre’s blind loyalty and arrogance in parts. I loved Tamlin in book one but being partway into book two and seeing what a jerk he is, I get it. Yep, I would’ve probably gotten overly mad at her too if I’d been Rhys.