Book: Throne of Glass
Scene: Celaena is sick and she throws up everywhere as Chaol comes in. He tucks her into bed and asks why she's sick and when she mentions her "monthly cycles" he freaks out and leaves.
Page: 255
Quote from page: "'Chaol,' she warned. As he pivoted, Celaena vomited all over the floor.
He made a disgusted noise, jumping back a foot. Tears sprang up as the bitter, sharp taste filled her mouth. She hung over her knees letting drool and bike spill on the floor."