Hermia does not want to sleep with Lysander until they are married. This scene occurs in Act II Scene II. Hermia has run away to be with Lysander instead of Demetrius and expects to be married to him soon, but she believes that proper maids and bachelors do not sleep together before marriage. Lysander tells her that he only wanted to sleep close to her innocently, but she resists. The following quotation is her response to his suggestion that they sleep side-by-side:

But, gentle friend, for love and courtesy
Lie further off; in human modesty,
Such separation as may well be said
Becomes a virtuous bachelor and a maid,
So far be distant; and, good night, sweet friend:
Thy love ne'er alter till thy sweet life end!

In this same night, Puck puts the love potion on Lysander's eyes because he was instructed by Oberon to give it to an Athenian man without specifying which one. Lysander awakes and falls in love with Helena, the first woman he sees. The crazy web of misplaced love begins to unravel from here.