The large gap made my mind think about the old -- and some might argue sexist -- "half plus seven rule," which has shaped cultural understandings of what is an acceptable age gap in relationships. It's a simple math equation that most often comes up these days in references to relationships involving older men and younger women. You take the older partner's age (50 in the example above), divide it by two (25) and add seven (32). If that number is smaller than or equal to the younger partner's age, "the rule" suggests that younger partner is old enough for the older partner to date. And if it's higher, that suggests the younger partner is too young.

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