Your hypothetical road map regarding the progression of sexual practices that we will see in the game both intrigues and puzzles me a bit.
It intrigues me because, frankly (as we all are), I am looking forward to seeing Sophia engaged in something more interesting than what we have seen so far (mostly petting and teasing) and it puzzles me because I don't think this can happen with the mere strangers who are currently the guys at the Museum of Modern Art.
OK, San Alejo girls are easy, but not to this extent (at least not Sophia, who recently moved in and still hasn't gotten used to local customs).
Jason and Haru (the guys from the museum) we have only seen them once, and I don't think Sophia's level of "conscious sluttiness" is already capable of allowing her to do anything more sexually charged (like a blowjob) to a stranger. However, I agree with you, with the idea that the time is ripe to start practicing something more interesting. So what?
I know his character is not among your favorites, but what if Sam got involved?
Maybe Sam's sudden artistic talent in this morning's event (Day 20) was just a good excuse to justify his interest in the art world (and thus his likely placement in the Day 21 evening event with an after-hours visit to the San Alejo Museum of Modern Art). Maybe this could be a good opportunity for Sophia to impart some lessons to Sam about the modern art he so mistreated. Maybe she could find a way for him to appreciate certain masterpieces that I am sure will not be lacking in the museum's various galleries (Picasso, Dali, Pollock).
Don't forget that Sophia owes Sam two big favors: one more practical (picking up Ellie who was left alone on the beach on the evening of Day 19) and the other more intimate (giving her her first orgasm in 13 playable days). The invitation to this special evening at the art museum might be a good way to reciprocate the former (as well as ensuring her stimulating company for the visit and a chauffeur service for the ride home) and probably the post-evening (in a more secluded place like Sam's car) an even better way to reciprocate the latter (with the continuation of what was interrupted on the evening of Day 19 - see screenshots below).
The event could follow the pattern (now well-established by the latest updates) of a softer first part (that of the museum visit) followed by a second part more interesting in terms of erotic content (that of the car ride home with Sam) in which Sophia could repay all the favors her young and caring neighbor has done her so far (cello lessons excluded).
Similarly to what we saw with the end of Day 20 concerning Dylan, the event could be split into multiple parts, and those not interested in the Sophia/Sam game path could follow the continuation of Patricia's evening with Jason and/or Haru (this could be another L&P update of easing the focus away from Sophia's character, which, IMO, would still be interesting because it would feature a character beloved by so many and whom we have so far never seen in action). It could be a way for L&P to even the score (in the time of two consecutive nights) between Sophia's two main contenders and between two of the most beloved (and consequently also most hated) characters by fans of his game.
For me, as for you, the assumption applies that I have no supporting data for this theory of mine (I also think it's too early to ask L&P directly - and, anyway, even in case I was right, he would surely be at least vague about it). This is just another speculation, yet another outpouring of the ever pawing horses of my imagination along the endless meadows of possibilities that this game (after seven years of development) still offers, but it is the best I could come up with to combine the need for something hotter that this game has and the story as it has been told to us so far.
