Eighteen years in the Mithila narrative universe is a deliberate span. It represents:

: Relationships starting around age 18 often face high turnover, but those that survive into the late 20s (like the characters in Little Things ) tend to shift into a "romantic-committed" stage. National Institutes of Health (.gov) sociological data on long-term relationship trends?

Intimate scenes (tasteful, emotional, and physically mature) come in matched pairs: