In the episode "Clumsy Monkeys and a Tilted Uterus. Luke is offered a job at Jeff's software company learning to design video games. Jeff and Suzanne were the people who adopted
Violet's baby. And once the adoption was completed Jeff decided to take Luke under his wing.
At the same time, Luke had promised that if Jeff ever wanted another kid he could make that happen. All of that is forgotten here. Luke has to explain where he's working and what he's doing.
Even though everyone was in the room when he was offered the job.