I'm trying so hard to chalk this misunderstanding (for the readers) up as "all penetration is sex", because there's like zero chance Bai Man mistook a hand as a penis lol - Even a virgin can tell the difference 😭 But Zhou Rings teasing aside, Bai Man keeps using words and phrases that explicitly mean intercourse in either language.
Like for me personally, I count digital penetration/fingering as sex, and I imagine most sapphic women feel the same, but I don't know if that's a cultural thing or not. I know in the states there's a much bigger presumption that sex involves a penis, but I have also encountered that mindset on the mainland.
This isn't even a major plot thing but it's bugging the shit out of me trying to figure out if Bai Man is just That Dense™️ or if it's a cultural difference on what "sex" entails