To: When I was 12, I sent n*** pictures to my boyfriend at the time because he kept asking.
Me: He did not make you, you submitted to his demands for whatever reason, but one gives you ten, if you were together, he would have seen you n*** and probably played with your body and possibly fucked you too, so sending him n*** photos really does not mean much, in the scheme of things.
If he never showed them to anyone then no big deal, if he did, you are not 12 anymore and you won’t be ever again and I bet you don’t even look like your 12 year old photos, so you can deny it was you who took them, if ever anyone asks and then it is down to he said, she said and if you deny everything, it will all blow back on him, anyway.
If you did not take any photos which included your face, then I don’t see any problem at all and in all probability he does not have the photos anymore – so don’t worry about things which won’t ever affect you.
He can’t show them to anyone, because if he does and it turns out you were 12 and a minor, he will get severely punished and probably end up in prison, as he well knows.