When a small child sees through one's attempts at deception, the only appropriate response is to admit all, and then enlist the child as your collaborator.
Not surprised she's so tech savvy. She did take a selfie of them sleeping together when she was still a baby. That particular chapter is still one of my favorites.
I feel like this way telling their ending is too much focused on the way their interaction were most often a comic relief before.
I hope the other chapters of this ending will focus a little more on how a serious relationship between the two can develop and will not just be full of tropes and more comic relief.