You'll want to leave it out. if it isn't conducive to the content of your paper, it's more like a distraction from what you're trying to say. parentheses might be a "safe" way to signify a side topic, but it weakens the paper as a general statement because the reader has to pause and take a moment to absorb a new topic before going back to what you were saying
Answer:
The primary antagonists of the play include the Capulet and Montague families, whose longstanding feud restricts Romeo and Juliet's freedom and ultimately thwarts their love
