"I think the roles have been reversed. We're very immature, and she's very together," Perkins said.
Sarah Chalke plays their uptight daughter, and the two veterans also share many scenes with Rachel Eggleston, who plays their granddaughter.
Perkins says she definitely sees herself in her character, Elaine.
"I can be a little outrageous. I can be very outspoken. I can say what's on my mind," Perkins said.
Perkins also said she relates because her kids are around the same age is Chalke's character.
"The thought of them moving back full time is a little overwhelming," Perkins said. "You get to a certain age where you do start enjoying the empty nest. You enjoy the freedom of running around the house naked, and we put in the time."
"It's fun to be able to have a marriage where you're very much into each other later in life, and it's kind of our time," Garrett added.
"How to Live with Your Parents (For the Rest of Your Life)" airs Wednesday at 9:30 p.m. on ABC7.