In many of my stories, I depict victims as feeling intense guilt after orgasming during their gang-rape. The girl typically feels guilty that she didn't act "like a victim should". This is a huge taboo in our society, and many victims feel alone and left to themselves because what they experienced is something that no one wants to talk about.
It can be a purely physiological reaction and it absolutely can happen while the victim is utterly horrified and still unwilling. At any rate, this is always challenging to depict in a fantasy rape story.
Yeah, like your soul is being violated, but then your body suddenly floods you with "this feels amazing"
That's about the idea. It's always a challenge, as a male writer, to depict what goes on inside the mind and body of a woman who goes through this. I'm a lot more at home when it comes to describing the extreme levels of intensity male pleasure can reach during the act, but depicting the woman's experience is a delicate balance. It is easy to fall into the "she ended up loving it" trap.
Many victims in my stories lose control and develop a problem of self-hatred because they "didn't behave properly". She should have hated every second, but she did have intense bursts of bodily fireworks that she'll never forget.
There's a loss of control, and usually an extreme degree of confusion in the woman. Some girls basically shut down and remain kind of "frozen" and are very silent from beginning to end. I'd say there are as many reactions and post-rape journeys as there are raped persons. It is extremely personal, the most intensely personal thing in fact.