Perfect Strangers (1986)

S06E14 Grandpa

When Grandpa Appleton pays a visit, everyone is taken aback by his youthful spirit. At 76, he behaves like a carefree teenager and even has a girlfriend who is significantly younger. Larry believes Grandpa should behave more in line with his age, while Balki argues that it's perfectly fine for him to embrace the age he feels inside.