"Okay," Eli replied to what Noah told him. He had already come to terms with there being a lot of secrets about Helen at this point. She was telling him at her own time and every time they spoke about her, she revealed something else. He would just have to wait for her to tell him about her identity.
After hearing she killed her own parents and the fact he knew she killed a vampire, the secret identity wasn't surprising. Her real identity being hidden was almost expected at this point.
"Okay? Okay! That's not what a logical person says in this situation, Eli. You should be concerned to know who the hell you've let into your home. I like Helen but I would lock my door so that she couldn't-"
"She is upstairs taking a shower," Eli said in a bored tone. If Noah was a human he would probably have a heart attack by now.