One of my favorite passages from The Namesake. It's a little bittersweet -- does the phrasing "he believes he has known" foreshadow the fact that he doesn't know her? -- but I think it captures those moments, when you first begin to seriously start dating, and get to know one another's little peccadilloes.
"Within three months they have clothes and toothbrushes at each other's apartments. He sees her for entire weekends without make-up, sees her with grey shadows under her eyes as she types papers at her desk... He sees the hair that grows on her legs between waxings, the black roots that emerge between appointments at the salon, and in these moments, these glimpses, he believes he has known no greater intimacy."