Only Pushing Daisies could make kissing through plastic wrap romantic. It's amazing what an innocent, fairytale relationship can get away with!
While Ned hasn't been honest with his rescued princess that he accidently killed her dad, he did come clean about the other guy (physically) close to her who he accidently killed.
Though she could accept him letting a nasty funeral director die for her, her dad would be a very different story.
As usual in relationships where secrets are kept, it's only going to become more and more difficult to tell her as things progress, but I can't really blame Ned for keeping this secret when they've only just come back together.
On the topic of Chuck, I was completely understanding of why Chuck needed to be under cover and stay with Ned at first, but in this third episode, though I really want Ned and Chuck to be together, I'm wondering why they can't just make up a story as to how and why she's still alive.
It's not exactly like Ned's protecting her besides hiding her. It's actually more dangerous for her to live with Ned since his touch can kill her where as if she went out back into the world, only normal fatal incidents could take her out again.