Something a newlywed usually lacks

ALONETIME

Think about what becomes scarce when you're constantly sharing space and plans with someone else, especially in the early days of marriage.

This clue plays on the idea that newlyweds are often inseparable after marriage, jokingly implying they rarely get time apart. "Alone time" is split into "alone" and "time," but written as one word to fit crossword style. The humor comes from the relatable stereotype of couples spending every moment together in the early stages of marriage.