That's Edgar, another CTU computer whiz. He is on his 3rd season I think. He was acting weird tonight but I don't think it was directed at Chloe. They worked together on stuff last season(helped each other out on things).
I think Edgar likes Chloe, and doesn't like this new dude.
I thought Edgar likes Chloe, but assumed she would never do anything with someone she worked with. Then he finds out she slept with the new guy. It's taking him some time to process that information.