Spoilers for the game below.

Every mention of rape related to the game I can find is talking about the implied rape of the protagonist's friends. There is an actual on-screen rape in the game though and no-one seems to have noticed. The protagonist is given a hallucinogen and then wakes up having sex. The protagonist does not seem to be bothered at all about this in the game.

It is described as a sex scene everywhere I have found it.

http://www.youtube.com/watch?v=c0tM0m80zvo