The Loud parents are suffering the 40s' crisis, so they try to be "younger and hippier", much to the siblings' annoyance.
It's family fun day. The parents decide to do whatever they children want for today. Lynn Jr. suggests baseball, and at first the others refused, later they choose to do that because the others' ideas weren't too good.
Already in the field, two teams are formed, with their respective captains, Lynn Jr. and Lincoln. Lynn Jr. picks both parents, because she wants to be generous. It's Rita's turn at bat. It seemed she could do it, but when she does the movement, a crack is heard coming from her hip, so she fails and has an strike. The same repeats twice, so she receives an out. Lynn Jr. complains with her for that. Later, Lynn Sr. has to catch the ball. When he lowers to have a better angle of vision, his knees give the same crack sound, so he falls on the floor, and the ball flies over him.
Once at home, Lynn Jr. goes into her room annoyed, angry for having lost 17 runs to 3 at Lincoln's victory. When the door closes, the parents analize what happened. When they do end, they notice they're passing through the 40s crisis. Assuming they have between 44 and 48 years old each, it was expected. So they start to obsess with their physical aspect and personality. Casually Lincoln listened that, so he goes to tell to the sisters, who act worried and annoyed they're going to embarass them.
The parents start to have a paranoia, so they start changing their outfit, quitting their jobs, and doing useless spendings, like changing Vanzilla for a motorcycle. The siblings start to worry a little more. The parents start to involve more in their children's personal activities, thing that bothers everyone. But all has a limit. When the parents thinking they're young again, uploaded embarassing photos of their children to internet, they felt very displeased.
The parents, at listening that, notice they reached low levels, so they decide start to reconstruct their lives. First removing the images from internet, later apologizing to their children, who aren't very happy with the thing they did. The parents sell the motorcycle and got back Vanzilla, at the same time their jobs. Now they use part of their retiring funds for therapy. The therapist says this is normal. But the problem with their children still was there, along with their physic..
So the parents start to do exercise to have a healthy old life. Now it's time for their annual medical checkup. The doctor says their health has considerably improved. But they still have to regain their children's trust. Lynn Sr. knocks Lynn Jr.'s door to talk about what happened. He explains her it's normal to have the forties' crisis, and that's not a thing for being annoyed. It's part of the life of a grown-up, sooner or later, everyone will have it. Both of them manage to reconcile. The other siblings heard that, and accept the forgiveness.