Lyndsey's mother is visiting and both Alan and Lyndsey are showing her around Los Angeles. Her mother, named Jean, played by Georgia Engel, acts sweetly, but voices disappointment in her daughter and grandson in a similar manner to Alan's own mother, Evelyn. So they experiment this by introducing Evelyn to her mother. At first, the mothers don't like each other, but they bond and go out after Alan and Lyndsey head home from dinner. In the morning, Alan and Lyndsey are shocked to find their mothers sleeping together. Meanwhile, Jake and Eldridge want Walden to hire them as consultants who come up with new app ideas for his company. They get Walden to drive them to a party, but they have the wrong address details.