Juliet giving her father the finger (the wrong finger) must be one of my favorite moments in the series. Not only because how she said it was hilarious, but because of what she said.
Threatening people with family ostracism has been a tried and tested punishment in fiction (and in real life 😔), to the point that characters seem unable to react. Juliet is one of the few examples I can remember of someone turning that threat back against their parents:
"No, you won't kick me out, I'll leave on my own!"
EDIT:
@Xystus Agreed. I mean, from the moment this manga started, did anyone have any doubts that Juliet and Romio were going to end together, mend the Touwa-West divide at their academy and convince their families to approve of their relationship? Heck, I'd say that this series has managed to defy cliches and tropes more often than the competition (which might not be saying much about romcoms, but still).