If there is a remaining risc,

who has to decide if this risc is small enough?

The child, the pedophile, the parents, authorities?

The inherent problem of this question is that it uses a question which seems to be complicate - the evaluation of the remaining risc. The implicit but wrong suggestion is that it is necessary to make such an evaluation in every single case. This is a modification of the same problem as with the principal question about the remaining risc. Indeed, we know that there is a remaining risc for playing soccer, but nonetheless we usually leave the decision to play soccer to the child.

The other problem is that it suggests that control of the sexual behavior is something which is natural: "who has to decide" instead of "is it reasonable to try to control". Indeed, it neglects that people who want to make love with each other never ask other people for permission.

Independent of these problems, there is a clear answer: The decision ot make sex will be made by the involved persons, thus the child and the pedophile.

Because this was the obvious aim of the question, we have to consider the following reply:

But the child cannot evaluate the risc correctly, and the adult is interested in having sex and that's why will ignore or minimize the risc.

This is again a variant of the power argument. Indeed, the adult may have the power to hide a certain risc from the child and to use this knowledge against the interest of the child. But this potential possibility doesn't mean that the adult will really misuse his power.

If we assume that the adult loves the child and does not want to harm it, there will be no danger that he hides a risc from the child.

After this, some additional observations may be added:

• The greatest risc for the child in a consensual relation is the greatest danger for the adult too - discovery. And discovery is more harmful for the adult. Thus, it is already in his own, selfish interest to protect the child from this greatest danger.
• Other potential risc factors are feelings of shame and guilt. They are dangerous for the pedophile too, because they can have the result that the child tells. This is true for almost every other problem of the relation too.