Neither character interacts or even knows about each other, but because both are parental figures to Louis, some people ship them and even make fan content of Louis being raised by them as a couple. In fact, it's likely the story ended with Louis being unaware of Jack's very existence.
Jack/Louis is a ship that is surprisingly popular, even though neither character interacts with each other in canon.Yomi and Sakaki from Azumanga Daioh are a semi-popular ship, even though the two barely exchange words with each other.
