One night, it might be the 3-year-old's favorite, "Peter Rabbit," the next it could be "Good Night Moon."
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That they are separated by an ocean doesn't seem to faze either person.
While grandfather reads, grandson laughs and asks questions.
It's all possible thanks to modern technology.
The two have become fluent in Skype — a software application that allows users to make voice and video calls over the Internet.
Harmon lives in Hagerstown, Ethan lives in England — but a little thing like distance doesn't keep them apart.
"I'm afraid that we'd be strangers if it wasn't for the computer," Harmon said. "It's the next best thing to being there."
There was a time when grandparents lived next door — sometimes in the same house.
Today, millions of American families are scattered around the world.
But that doesn't mean that grandparents have to be relegated to a token role in their grandchildren's live.
"The bond can develop," Harmon said. "It just becomes a bit more challenging."
Harmon said he feels it's important for families to relish intergenerational relationships. That's why he works hard at staying in touch with his grandson, who was born and lives thousands of miles away.
Nearly half of American grandparents live more than 200 miles from at least one of their grandchildren, according to an AARP study, which also found that about two-thirds of grandchildren see one set of grandparents only a few times a year.
But many long-distance grandparents are finding creative ways to stay in touch, the study noted — including emails and using Skype.
Dara Bergel Bourassa, assistant professor at Shippensburg University and director of the school's gerontology program, said you can't underestimate the importance of maintaining intergenerational relationships, regardless of how many miles separate you.
"Grandparents have always been an important aspect of support for the family," she said. "Grandparents provide the adult children and grandchildren with the opportunity to learn from their personal history."
Bourassa recently wrote about the importance of fostering relationships between grandparents and grandchildren in an article published in Psikologji, an Albanian psychology magazine.
"One of the joys of grandparenting is seeing the life cycle continue," she said. "It is extremely interesting to see the grandchildren's personalities and physical characteristics develop. And one of the delights of grandparenting is that they often have the time to spend with their grandchildren, generally due to retirement."