It always seemed one highly probable logical progression, even though it's been done every year, for years, in porn mags & films, short stories, renders etc. We must all have thought about it. There's also the possibility that the milder next step would be to wear a thong, (aka g-string, string etc.), which is also a common feature of these stories. There's the issue of proof, which as you rightly say, is a factor with Aiden, (& every other villainous pupil in the tales I've encountered). This usually occurs through the wearing of a short, often tight dress or skirt & either bending down, or sitting with legs open on the front desk or table & bending as well, in the case of no panties, for the full picture. As the tasks have been incremental, I think the thong to be the more likely option. Unless of course L&P intends to spring another of his surprises. I really hope that if it occurs (& it's now a big IF) & the task is fulfilled, that there's no repeat of the totally unrealistic, (most unbelievable scene in the whole game so far), conversation & demonstration in Aiden's classroom corner that took place when Sophia showed her panties. This could never have happened with no-one else seeing or hearing anything. If anything similar was to happen, Sophia would have to be wearing one of her "floaty" sundresses, so that a quick flip up would be proof to Aiden & Dre & be more realistic than the second task event with those two.
Now we also have the question of whether it will happen at all. Yes, we have it listed as due in the next update but this could well be just the describing of what the next task is to be, unless of course Aiden were to demand that Sophia takes off her panties right then & there. If this happened & she complied it could at least occur before the teaching session. Then there's the proof issue again. Career damaging or career ending are just two possibilities, if a demo in front of the class was to take place. There is absolutely no way it would not be the 'buzz' of the school yard, for days, if not weeks, or months to come & then there's the nicknames that would follow.....
I have my doubts as to whether the task will be carried out & would refer you to my earlier posts, re the Morello connection. I regret we may soon see the end of the tasks, despite what has been shown as planned.