Guilt swept over him and he looked down for a moment. "A friend of mine and Clark's got into some trouble about three years ago." He hesitated, not wanting to bring up any painful memories, but knowing that in order to be honest, he had little choice. "Trouble of the Lex Luthor kind. Lex had been experimenting on people with abilities. Attempting to clone them and create his own army, I guess. And maybe he just got off on it."
He drew in a breath and let it out slowly, looking up at her. "It was right before I left Metropolis the first time. Chloe had figured out my other identity and she wanted to help. And honestly, we needed it. So while the rest of my team and I suited up to go rescue our friend, Chloe stayed behind and guided us through the mission through a comm device. And no, I would never intentionally put Chloe in harm's way, but...she does have that Sullivan-Lane gene that means she's magnet for trouble." He paused, giving her a moment to absorb that information and ask any questions that she needed to ask.