attempt.
Therefore thy kinsmen are no stop to me.

He tells her that he cannot be stopped by her relatives and that his love causes him to be daring because he is so drawn to her presence.

Just before Juliet enters in act 2, scene 6, Romeo discusses his feelings toward her with the friar:

But come what sorrow can,
It cannot countervail the exchange of joy
That one short minute gives me in her sight.
Do thou but close our hands with holy words,
Then love-devouring death do what he dare;
It is enough I may but call her mine.

Romeo says that whatever sorrow he has to face because of this choice to wed Juliet will be worth the cost. He only longs to be with her, and everything else pales in comparison in terms of concern or importance.

Their feelings intensify near the end of the play, and in act 5, scene 3, Romeo speaks to Juliet, who he believes to be dead:

Ah, dear Juliet,
Why art thou yet so fair? Shall I believe
That unsubstantial death is amorous,
And that the lean abhorrèd monster keeps
Thee here in dark to be his paramour?
For fear of that, I still will stay with thee,
And never from this palace of dim night
Depart again.

Without Juliet, Romeo cannot move forward in life. He therefore determines to join her in death so that they can never be separated again.

Likewise, when Juliet awakens from her fake death and finds that Romeo lies dead beside her, she decides that she cannot live without him either:

What's here? A cup, closed in my true love's hand?
Poison, I see, hath been his timeless end.—
O churl, drunk all, and left no friendly drop
To help me after? I will kiss thy lips.
Haply some poison yet doth hang on them,
To make me die with a restorative.

Thus, the two lovers who proclaim that they can't live without the other bring their thoughts to fruition by play's end, concluding in a great tragedy for both of their families that highlights the effects of bitter animosity.

Yes! In fact, both Romeo and Juliet say out loud a few times each that they'd rather be dead than live without each other. The poor Nurse and Friar Lawrence have to listen to their dramatic claims. Let's see what they say exactly:

1. In Act 3, Scene 2, Juliet tells the Nurse:

"Hath Romeo slain himself? Say thou but 'ay,'
And that bare vowel I shall poison more
Than the death-darting eye of cockatrice.
I am not I if there be such an I,
Or those eyes shut that makes thee answer 'ay.'"

She means, "Is Romeo dead? Okay, if so, then I'll kill myself."

2. A moment later, Juliet adds:

"Vile earth, to earth resign. End motion here,
And thou and Romeo press one heavy bier."

Meaning that if Romeo really is dead, then she'll kill herself, and she and Romeo will be together in one coffin. 

3. And another moment later, Juliet also says this, meaning that she'll let death take her virginity rather than Romeo, since he's banished:

"Come, cords.—Come, Nurse. I’ll to my wedding bed.
And death, not Romeo, take my maidenhead!"

4. Soon afterward, in Act 3, Scene 3, when Romeo finds out that he's been banished from Verona, he says:

"There is no world without Verona walls
But purgatory, torture, hell itself.
Hence 'banishèd' is banished from the world,
And world’s exile is death."

He means that he'd rather be dead than be banished from Verona, where Juliet lives.

5. He goes on to say to the Friar:

"Hadst thou no poison mixed, no sharp-ground knife,
No sudden mean of death, though ne'er so mean,
But 'banishèd' to kill me?—'Banishèd'!"

He means, "Don't you have any way to just kill me instead of sending me away from Juliet?"