Responses

You're definitely not stupid for not knowing and asking. Dubcon means "dubious consent". I guess a popular example would be a sex scene involving a character who may have doubts in their mind but does not say it out loud to their partner.
It is used very very often to describe what are actual rape scenes. For example sex scenes involving characters who are drunk; relationships between teachers and underage high school students; characters who say no quite clearly but who show signs of physical arousal, like in this chapter.
What's interesting to me is how the warning of rape from the platform shapes responses in the comments. (So I speculate, can't know for sure.)
I've read lots of other stories with this exact kind of scene. Comment sections would be split between those who saw it for what it was and those who would go "It's not really rape!" or "Okay, but remember the seme has issues!" to make it seem like it's not a big enough obstacle to the ~romance~.
Interesting...if true.