Unfortunately, we find out that David is such a deadbeat dad that this news actually upset Harris (hence the cakes), because since leaving Darlene he’s only shown up three times when he said he would.
Roseanne says that she thinks David will actually show this time, and Darlene realizes that she’s been talking to him behind her back and giving him updates on Darlene.
We’re also told that David has been spending his time away from the family building houses for the poor in third world countries, so he’s rarely even in the same country as his kids.
When Roseanne, Mary, Darlene and Harris are grocery shopping, a clerk tells Darlene that Harris has abused a bunch of cakes in the bakery, and when Darlene gets a text from David a few minutes later, she realizes that he had already sent word to Harris that he was planning to come see her for her birthday the next day.