It's most likely a bug and "flirting harder" should set it to True (instead of redundant False) given it leads to Fuckface and Bianca doing sex things. The beta testers would overlook that because without looking in the script you don't even know it's there, as it has no impact (yet).that seems like a pointless variable at the moment, nothing in episode 11 actually changes its value.
(as for why it's called Ep11 and not Ep12, that's because all variables are named after the chapter where you can make decision which potentially set them. Which would further confirm not being able to activate it there is unintended)