To me it doesn't feel like any of em add much to the narrative. The mom wants to fuck her son the sister wants to fuck her brother and that's about it. Neither of em add anything outside of wanting to fuck or being in love with their son/brother. It's just one of those games unfortunately but the story with the drug/trafficking stuff is intresting, id say it's the only reason why I'm still playing this game.
Well, that's what doesn't interest me in any way. There are by far better media to tell a story about drug/trafficking.
I am interested in this game because of Tris. Is it a complex story with lots of depth? Hell no. The teasing is fun, the renders are nice and that's about it. And it is enough. When I want elaborated stories, I read a book.
Who knows, maybe he'll come up with something to do for the two of them other than circling around each other.
I usually like stories where they do come together and then there's an actual plot following that.
And that's why I prefer VNs with fewer LIs. It's impossible to find something to do for all of them and still keep a certain release rhythm. I'm not so much interested in all the 'harem' variations that are possible, but more in a story for a few of them or even stories with just one. One of my favorite VNs had one LI, and a option to chose one of 3 other characters, some minor side events. But it was all focused on the one char.