"Th' exchange of thy love's faithful vow for min" (2,2,134) Romeo and Juliet know that their parents hate each other, they are supposed to hate each other as well, but they don't. Which ends up with them marrying each other
"To fetch a ladder by the which your love, Must climb a bird's nest soon when it is dark" (2,6,78-79) The nurse agreed to set up a ladder so that Romeo can ascend to Juliet's room on their wedding night, knowing that they should not be getting married.
"Is she a Capulet? O dear account! My life is my foe's debt." (1,5,131-132) This is when Romeo kisses Juliet, then later realizes that she was a Capulet and is left feeling confused by it.