Okay maybe I'm confusing this series with another one but what? "You shouldn't assume someone will sexually harass just because they're gay"? She DID do that. She was all over her, ignoring the hard, explicit nos.
I'm fine with comedic dubcon, but don't flip a switch with the tone like her reaction to that question reveals a problematic bias. If you've been reading for this long, you've accepted Rei's behavior - the sudden seriousness makes her prior actions look worse.