>>22591442Half-you-age-plus-seven is usually used because it gives a better idea of what stage of maturity the couples are at individually, the older the people in the relationship are, the wider the margin becomes.
In that case, the youngest person you could date that would be socially accepted as being your "equal" in terms of maturity when you were 18 is 16, which makes sense to me.
Then again you're clearly not being serious and just trying to be a Trick Master so it's null and void.