Hi again, Ewan and you're most welcome!
Thanks for your patience. I had an appointment and was offline for a while.
----Where would the troll start to tear at the boys tight blue swim suit to remove it ?
He would start to tear at it from the front, at the waist.
----How and were would the troll then start to feed on the boys genitals,would it swallow the lot hole.
No, he would not swallow the lot, whole. He would start taking bites, chewing, swallowing, and then continue tearing off more flesh with his teeth until it was all eaten.
----What would be left after the troll had finished feeding and what would happen to it .
The troll would not eat the whole body, so there would be some meat left on the bones and the bones, themselves; he would not eat the bones; he would not eat the head. The body would be quite mangled and after he finished feeding, other trolls would eat what was left.