This too is another common early recovery issue. We are often confused especially in our late teens and into our 20s, when we have suffered a bunch of abuse at the hands of male abusers if we happened to orgasm as a result. Remember, you were a kid that was used for someone else's pleasure and it wasn't your fault. The male organ responds to stimulus, even abusive stimulus, which is somewhat cunfusing to many victims. You will work through this issue in therapy too.
Maybe someone else would be able to offer more perspective on this issue.
Have hope, with a lot of effort and our support, recovery is possible.
"We stay here, we die here. We've got to keep moving". Trucker Mark