Okay, so judging by that picture with Reylo being inside Snoke’s lair. I suspect the 3 of them will have different motives for Rey being there.
Snoke - Will probably tell Kylo to bring Rey to him so that they can turn her to the Dark Side in a peaceful way
NOT. But that’s obviously a lie since he knows Rey is Kylo’s weakness, so he will order him to kill her. Kylo will probably think that Rey will join them or that Snoke will let Rey walk away if she says no to his offer…. being a bit naive.
Kylo - Wants Rey to join him but he knows that Snoke knows this, so he has to bring her to Snoke for approval.
Rey - Tells Kylo that she will agree to meet Snoke and maybe join them
but in reality she just wants to kill Snoke.
I don’t think Kylo will actively try to kill Snoke in TLJ, but I think he will be forced to pick sides between Rey and Snoke. And so he will chose Rey and defend her.