My understanding of what's going on for people who are confused: she's playing the social "game" of "pretend I don't want the thing I actually want so I don't appear demanding and instead make the other person insist". Everett understandably finds that "game" annoying and basically tells her to go fuck herself for playing it.
Ironically it's actually kinda unintentionally progressive imo. He's basically forcing her to actually speak up and assert herself instead of playing the "make the man tell me to do" game.
It's kinda like how Japanese culture expects for you to deny a gift up to 3 times before accepting, but more gender-focused and misogynistic. Everett is basically saying "fuck that game, if you want the seat, take the seat; don't play games with me and waste my time."