The bigger question, which is useful to gauge how far along Sophia is in her journey towards straying, is what will end the upcoming scene:
A) She is able to put the brakes on herself once it starts to go too far, or
B) She will be saved by an interruption that takes her out of the moment.
The jaccuzi scene was effectively ended because Liam showed up. Before that, she was pretty much going with it.
Even the club scene a while back, when the guy was feeling up her leg, it was only noticing her sister watching her that pulled her out of the moment.
So I'm expecting Sam to be making headway, and there will be a knock at the door or something, yet again, that will let it only go to a certain point and then reset.