Hermia and Helena remain constant to their lovers throughout the play, whereas Lysander and Demetrius fluctuate, desiring first one woman then the other (as we are warned may happen in Hermia's early mention of "all the vows that ever men have broke" (I i 175). Yet in remaining constant to men, the young women destroy their sisterly friendship. The young men, on the other hand, sustain their relationship of loving the same woman and being rivals, only changing it at the end, when the couples are properly matched and the men can become friends rather than rivals. Thus Montrose writes that "marital couplings dissolve the bonds of sisterhood at the same time as they forge the bonds of brotherhood" (Montrose 1996: 111)

in the text:

Lysander wakes and loves Helena instead of Hermia in II ii 100.

related comments:

The lovers misunderstand each other and are tricked by language.

Love and marriage.