It could easily be sex-ed based and without any alcohol involved on Sophia's part.
Remember that, although there were extrenuating circumstances with the viagra, Dylan had a bit of trouble being able to get himself off. Maybe something could happen that makes Sophia concerned about his well-being in this regard, similar to how she was concerned that Ellie had ever properly masturbated before, and so Sophia decides to help Dylan with his "problem".
It's looks like the BB, I hope Dylan doesn't have Tunnel Syndrome
In both cases, Sophia is the passive one, she lets herself go. There is no overt sexual interest before the event, but during the event.
We are talking about Ellie, in Dylan's case, Sophia did not show sexual interest but curiosity.
So we cannot expect initiatives from Sophia, it has to be the circumstances (viagra, a blow, ....) or Dylan's move. But at this point, don't forget that Dylan (no Twist) didn't say anything about his problems with Aiden, so, if he is going to have a problem (physical pain) he will not say anything to his mother.
I see it as more credible for Sophia to notice something strange, ask Dylan about the problem, trying to help ....
Next "Coach Sophia" event is perfect for this, Dylan takes a blow to the testicles, Sophia looks at the damage, .... Here Zac may appear again.