When Montague and Capulet enter and see the disturbance, they want to fight, too. What do their wives say?

Enter Old Capulet in his gown, and his Wife.
 
CAPULET:
What noise is this? Give me my long sword, ho!
 
WIFE:
A crutch, a crutch! Why call you for a sword?

CAP:
My sword, I say! Old Montague is come
And flourishes his blade in spite of me.

Enter Old Montague and his Wife.
 
MON:
Thou villain Capulet!—Hold me not, let me go.(75)

M.WIFE:
Thou shalt not stir one foot to seek a foe. 

There you have it. And it's important to note that, even at this very first stage of the play, Shakespeare undermines the seriousness of the feud by emphasising the fact that it is being fought by infirm old men, more suited to the crutch than the sword, who are being chased around by their nagging wives. This is - emphatically - not bloody brutality. It's not The Godfather. He's trying to make it funny.