Karen just looks amused when he makes his confession, coupled with that guilty little look. Honestly, it makes sense. He's a good looking guy. And she's pretty staunchly determined to solve all of her own problems, but she's not immune to the appeal of having someone in your corner.

"Wow. That second time was the real choice, huh?" she points out with a grin, just lightly ribbing him. "Sounds like you're a regular heart breaker, Alfred. Should I be worried?"