It's rude to prevent someone from talking.
Jocelyn and her friends are discussing politics, and she knows her friend Derek has strong views that oppose hers.
Jocelyn wants her friends to be on her side rather than Derek's.
Jocelyn lets Derek express his opinions and rebuts them with the best arguments she can think of.
Jocelyn interrupts Derek every time he tries to say anything, so he doesn't get a chance to express his opinion.
Jocelyn examines her own views and Derek's more closely and is able to develop stronger convictions and more nuanced opinions.
Jocelyn's friends notice that Jocelyn is interrupting Derek and call her out for being rude and mean to Derek.