Fanon:Dennis Gallagher

Dennis Gallagher is a Sim who resides in Oasis Springs with his family. His family consists of his wife, Maria, their twin children, Celeste and Trevor and a third child, Tucker.

Dennis also has some family living in Willow Creek. His Willow Creek family consists of his younger sister, Karissa Gallagher, and their divorced parents, Lawrence and Maggie.

Background
It is implied that Dennis is born to Lawrence and Maggie in Willow Creek while they are both still teenagers. Dennis is their only child for many years until he becomes the older brother to his younger sister, Karissa. He then eventually meets and marries his wife, Maria before moving in with her in Oasis Springs.

The Sims 4
Dennis lives at Rio Verde in Oasis Springs with Maria. Not too long after that they are married and settled in, Dennis and Maria welcome their twin children into the world. They named their children Trevor and Celeste. Dennis currently works as a Live Chat Support Agent in the Tech Guru career in order to help provide for his newfound family.

One day, Dennis receives a call from his younger sister, Karissa. She asks him how their parents reacted to him dating Maria. Dennis responds that they reacted normally and assumes that she wants to do the same with her boyfriend. Then, he advises her to do what she thinks is best.

Dennis eventually visits his parents and sister for his grandparents' anniversary party. He is immediately welcomed by Maggie and Karissa's dog, Barney. After a dinner prepared by Lawrence, Karissa takes Dennis into her room where she reveals that she's pregnant. Dennis is then asked some advice. He says that their parents never discussed the fact that he was born while they were teenagers. He then advises that Karissa tell Maggie and Lawrence about the pregnancy sooner rather than later.

On Harvestfest, Dennis receives a text from Karissa wishing happiness. He is also told through the text that Lawrence had kicked Karissa out of the house for getting pregnant. It is unknown how Dennis stands on the relationship between his parents following this event.