In Shakespeare's Hamlet, Hamlet's relationships with the women in the play—which are not strong or healthy—have an drastic effect on the play's outcome.
During Elizabethan times, it was believed that to marry an in-law, as Gertrude does, was an incestuous act. Some part of her dead husband still resided within her (so they thought), so when she sleeps with his brother, it is as if the brothers are sleeping together. This is one of the problems Hamlet has with his mother. Then, when he discovers that his mother's new husband murdered Hamlet's father, he is completely disgusted by the man, and vows to avenge his father's death. He berates his mother in Act Three, scene four, asking how she could stand being with Claudius who is such an animal after she had been married to one as fine as Old Hamlet. Hamlet describes his father first, a fine man...comparing him to Jove (Zeus' counterpart in Roman mythology):
Look here upon this picture… (59)
See what a grace was seated on this brow;
Hyperion's curls; the front of Jove himself… (61-62)
This was your husband.
Then Hamlet draws Gertrude's attention to her present husband (Claudius)—offensive to look at by comparison to Old Hamlet...he asks his mother if she is blind?
Look you now what follows.
Here is your husband, like a mildew'd ear
Blasting his wholesome brother. Have you eyes? (69-71)
The trouble that arises between Gertrude and Hamlet is that he waits so long to speak to his mother. Had Hamlet approached her as soon as Old Hamlet had spoken to his son and revealed his murder, Hamlet and Gertrude might have been able to work together to expose Claudius before he became so desperate to keep his throne that he was willing to sacrifice everyone around him.
The relationship he has with Ophelia is very different. They have been sweethearts. When Hamlet learns of his father's murder, he pretends to act crazy to confuse Claudius. To find out why, Ophelia is sent to spy on Hamlet by the King and her father: she has no choice but to obey. However, had Hamlet taken her aside and explained the situation, her love for him might have allowed her to share with Polonius and Claudius only what Hamlet wanted them to know. He would also not have felt so isolated and acted so foolishly. Instead, he is unkind, rude and grossly insulting. He tells Ophelia:
You should not have believed me...
loved you not. (III.i.26-28)
Get thee to a nunnery! Why wouldst thou be a
breeder of sinners? I am myself indifferent honest, but yet
I could accuse me of such things that it were better my
mother had not borne me… (130-133)
…We are arrant knaves
all; believe none of us. Go thy ways to a nunnery. (137-138)
Hamlet is unkind. At the play, Mousetrap, that Hamlet has the Players enact, he is cruel to Ophelia again. Had he kept their relationship safe, his accidental murder of Polonius might not have hit her so hard. In fact, the loss of Hamlet and then of her father drives Ophelia insane, and she drowns. This is tragic. However, the dangerous aspect is that Laertes (Ophelia's brother) blames Hamlet for both losses, and chooses to avenge his father and sister's deaths dishonorably, working with Claudius to kill the now-threatening Hamlet. Had Hamlet cherished and protected Ophelia, she would most likely have been able to comfort her brother, and Hamlet would not have died by Laertes' poisoned sword.