In Shakespeare's A Midsummer Night's Dream, how does Demetrius feel towards Hermia and Helena at the start of the play?

At the very opening of the play, Demetrius feels that he
is in love with Hermia. In front of Duke Theseus and Egeus,
Hermia's father, he begs Hermia to relent to her father's will and agree to marry him,
which would thereby save her life or save her from other harsh punishment. We see
Demetrius beg Hermia to give in to her father in his lines, "Relent, sweet Hermia; and,
Lysander, yield / Thy crazed title to my certain right" (I.i.93-94). We further see
evidence that he believes he is in love with Hermia when he asks Helena where she and
Lysander have gone, as we see in the lines, "Where is Lysander and fair Hermia? / The
one I'll slay, the other slayeth me" (II.i.193-194).

In contrast,
although there is evidence that Demetrius was in love with
Helena before he ever laid eyes on Hermia, at the beginning
of the play, he feels that he hates Helena. We see evidence of his hatred in the cruel
manner in which he treats Helena when she follows him into the woods in pursuit of
Hermia and Lysander. He not only says hateful things to Helena, he even threatens her
with physical violence, as we see in his lines, "Tempt not too much the hatred of my
spirit; / For I am sick when I do look on thee" (II.i.215-126). He is even so hateful
and goes so far as to threaten her with rape, as we see in his
lines:

You do
impeach your modesty too much
To leave the city and commit
yourself
Into the hands of one that loves you not;
To trust in the
opportunity of night,
...
With the rich worth of your virginity.
(218-223)

The references to
her modesty and virginity are a clear attack on her maidenhood and a clear threat of
rape, showing us just how cruelly Demetrius is treating Helena, due to his
hatred.

Hence, at the beginning of the play, Demetrius believes he is
in love with Hermia and believes he hates Helena.