Let me explain something to you: just because someone takes drugs does not give you the right to whatever you want with them. Comparing drunk driving to rape is called false equivalency because people are not cars; they aren't objects.
Clearly, people under influence cannot consent, and even if Nat came there to have sex, who does she want to have sex with there? Surely, not anyone can just come up to her drugged-self and rape her. Also, what kind of sex does she want to have? We see she was willing to have protected sex but what if she doesn't want to do anal or unprotected sex or, as game says, she doesn't want to be DP. Also, for how long does she want to have sex for? She obviously didn't want to spend the night there, maybe she wanted to do it once or twice and leave.
Seriously, why is this such a hard concept to understand. Why does rape have to immediately have to be "she was forced under gun point" and why does someone willingly taking drungs equal they are free to be assaulted?
Very weird lack of humanity.