I think we are getting a bit too far off the deep end. This has all the hallmarks of a sharing, free love thing; that's all. There is certainly a bunch of "experimenting" going on - I agree that both Brandi and Dylan are going through something of an education here for them, but I would not characterize their reaction to all this until we actually see it, which we have not, not at all completely. Sure, I suspect Dylan will be/is shocked at first but they will be getting on board with this free love community, nothing more will really happen. We see their resistance is melting already. Dylan was already on board - until he saw his mom and then understood it's a two way street. But I would bet it's just some personal growth we will see - not the NTR/ No NTR discussion - which has no end or resolution. I don't think that is what Pegasus intends here at all. I think PS will just bring our main characters (along with Aunty maybe), into a Nudist/Naturist, free love community - the subject of many 1970's porn movies to light here. I really don't think he will get too heavy here with "moral" concerns, that is clearly not his style in this great illustrated narrative.
Edit; corrected names, twice - sheesh