Ren's eyes narrow slightly, but other than that, she's doing her best not to give a reaction. It's obvious that's what Izaya wants.

It's more the fact that Izaya wants a reaction out of her and tried to target this that irritates her.

"So my Akechi's not here then. Got it."

Perhaps that is in and of itself a good reaction for Izaya, seeing as the tone ended up more curt.

Against herself, something does slip out though.

"By the way, you can just say their versions of me are guys. It's not like it's a big secret."