I'd guess that those story connections will be optional and you basically unlock them by reaching a certain point in both stories. I'd say you'll have to have sex with both of them in their stories first and then you can get the threesome. If you don't reach that point in both you'll continue as normal in their respective stories until you unlock it.
Hummm... While it would make more sense, it is hard to say, that is typically not how the game works, but in this case it is entirely possible, or it could just be a one-off thing, maybe mom is REALLY drunk, like seeing Eve's tits- ...er I mean partying with Eve in the Teachers' arc. 
I guess you'll need to progress both stories, it wouldn't make too much sense otherwise, and if we have to take into account the overall quality until now I guess they will deliver quality for this matter too.
It just depends on how it plays out, Maybe mom is really drunk, or Diane set it up with her, not saying who you are, and you are wearing a mask or something, there are a lot of ways it 'could' play out if they want, just look at the mom route in Sisterly Lust. At least it's not like Superpowered, where you have to do all of that grind all over again each time. I don't really mind for this one, especially since with any luck, it will only be a few more times after this.
people complain about doing everything from the beggining on SS,i don even care about that anymore,after the number of times i played Superpowered from zero......
From what I have seen on streams (sprites for Debbie and Diane sitting in an inviting manner on the bed in sexy lingerie) and guessing that this threesome will be a replayable event (it's a unic, epic and long awaited scene, it would be a shame if you can do it only once), I don't think a one-thing event would work. And it would still not work anyways, if you have had sex with Debbie and then you start her story it wouldn't make sense for her to be that hesitant.
Yeah, while I don't remember the teaser, it could go a lot of different ways. Considering Diane asks (asked) you about if you want to sleep with Debby, whether you have or not, she seems down, and IIRC they used to share Dad and maybe others back in the day. They are twins, and twins doing things together is a popular trope, and I am sure two adventurous young women like them were all about putting on a show and more.
the house you can buy is going to be such a cool feature (sort of like poker, the telescope etc) if it ever gets finished and filled with content. i sort of hope you have to convince a character to move in for you and you can then see her around the house, have some unique dialogue stuff happening and some unique and new h-scenes maybe even your wish combination for threesomes with certain other characters
In what way "about"?
well,today he didnt stream cuz he said he was sick,but Dogeek was working as usual,by the way people were talking on discord....
No one knows. Presumably within the week, but that's pure speculation based on what appears to be left.
