Evan, what Larry says above is 100% without a doubt correct. As survivors of this sort of "sickness" that we have been unknowingly exposed to, we must give ourselves permission to not be held accountable for any desires we felt at that age, that were being so inappropriately carried to completion.
Sexual desires are a very adult matter. Unfortunately, testosterone is released and starts climbing to very high levels, very fast when boys are starting pubescence (I like that word better than "puberty"). That's why an abuser will sometimes tell a pre-pubescent child that what they are doing is a "game", because they know that children love games and this is the perfect bait to get the child to participate. What the child doesn't know is that his body is going to respond to some degree (they can still feel sexual pleasure, but they don't know that's what it is). The mysterious feeling of sexual pleasure is what usually brings them back to play the "game" again, and quite often to get other children to play it too.
I think that once testosterone gets going strong, the desire to seek out that pleasure becomes overwhelming. Most adults have difficulty controlling their sexual urges so you can just imagine how hard it would be for a child.
I remember there were times when I taunted my abuser too, I wanted to make him beg, and he did. I remember he wrote something down on a piece of paper and passed it over to me because our brothers were in the room. I think he wrote something like, "let's go upstairs" and then "I want a bj". I kept saying no and he started begging. It made me feel like I had some control, and it actually made me want to do it even more.
You're definitely not alone with this one. I think it's what ultimately makes us all carry the baggage around with us, we think we did it to ourselves.
Guilt and shame have never done any of us any good at all.