I would not say that the Si caregiver is 'dominate' and the Ne infantile is the 'submissive. Like @
necrosebud mentioned, the Si caregiver more so 'takes the lead'. Have you ever tried to control an infantile? LOL it is not going to happen
Unlike victims, the worse thing you can do to an infantile is make them 'choose' or 'contain them. Especially in regards to seduction. IMO The Caregiver rather takes the lead on where the infantile wants to go sensation wise. Si is all about personal and internal sensations and since infantile are very receptive to it, I would think they would be more reactive of the Si caregiver taking the lead and showing them where to get the most bang for their buck so to speak. I think the roles may switch once the infantile gets comfortable and start using the Ne possibilities to show more options or alternatives. In the sense, Ne wants to try this possibility, gives the vision, and the Si can envision the sensation and make it happen. The roles tend to not be concrete, rather more so taking turns leading and following rather then dominating and submitting. That is how I would envision it theory wise and what I would rather have personally.