Of course, it has to be logical but the way Ava is looking at Sophia in the picture, makes me think Ava likes Sophia in that very tight top or she is questioning Sophia on her choice of top. So next update won't have sex but I do think we have a clearer idea of when Sophia finally be corrupted.
The only way anything happens in the next update is if the boys blackmail Sophia I think.
With this picture I would just assume that the kids were enthusiastic about Sophia.
And that with their enthusiasm they gave Ava the security that they made the right
decision with Sophia. And that Sophia is amazed and happy about it. Not more.
Why should the boys blackmail Sophia? For sex that the boys have no idea about?
I don't think there will be any physical action between the boys and Sophia.
But we have a similar situation here as in prison. Sophia controls the situation, intellectually, emotionally and physically.
I also expect bare skin at this event. Sophia will enjoy it and at the same time be ashamed of it. Nevertheless she will continue she has an educational mandate!

And I think a masurbation scene awaits us. Not this time, but at the next homeschooling event.
And let's face it, worse could happen to the boys.