All these people saying the MC should just go with it and have sex and how it's a "win-win" and how he's a loser for not sleeping with all the girls and whatnot have to be kids who are still going through puberty. I mean, the average, normal person is not some sex-obsessed manic who only thinks with their dick and feels that "conquering women" or whatever is what makes you a "man". If put in a situation where you're being forced against your will like this, of course you're going to resist. If a complete stranger asks you to have sex with her, the normal response would be confusion and refusal, not blind acceptance and excitement.
Obviously there are some sex-crazed people out there; people who feel like whether you have sex or not is what determines your worth as a person and as a man (such as people who use "virgin" as an insult), and people who think that the more sex you have, the better, but those kinds of people are in the extreme minority.