Research has found that the age gap between a 20-year-old and a 40-year-old can cause more issues than the gap between, say, a 50-year-old and a 70-year-old. Those potential issues diminish with age, however.
How much age difference is bad?
Half-your-age-plus-seven rule An often-asserted rule of thumb to determine whether an age difference is socially acceptable holds that a person should never date someone whose age is less than half their own plus seven years.
Do age gap marriages last?
Both men and women report initially being more satisfied in their marriage when their spouses were younger, research reports. Though couples with an age gap started out more satisfied, however, their satisfaction tended to drop more dramatically over time than couples who were the same age.