Turns out that "Grey" is a surprisingly popular boy's name in AVN-land, based on my sample...
Until the game is finished, all we can do is speculate. Based on what's happened so far, a harem seems unlikely, but not impossible (depending on how you define "harem").
As Season Two ends, you have a choice between 5 paths - 4 specific relationships, and "others" - but, if you've pursued more than one of the four main relationships, depending on the combination, you will see hints that you may find your way into a threesome (and one of the four relationships is a throuple), and the "Main Girls" are getting increasingly friendly as a group, so, if DPC wanted to go there, the ground-work is in place for a five-girl harem, possibly with occasional guest girls.
On the other hand, there are also strong hints that the throuple will break up, and the other main girl who offers threesomes seems to be souring on the idea when it becomes a reality rather than a horny fantasy. Meanwhile, the others path keeps making you choose between side girls - keeping one by dropping another. It does seem like DPC doesn't believe polygamy is viable, in which case, even if you can get some threesomes, the game's likely to end by forcing you to choose at most one partner.
Overall, I'd say even a limited harem ending is unlikely, but it's probably worth focusing on more than one woman in order to potentially get certain combinations.