going by how Jenny was getting on with Roxxy it doesn't seem like a threesome with the two of them is very unlikely, it's the next most obvious evolution of the cam show, after that Debbie catching everyone filming and so forcing a confrontation seems like the next logical step forward towards family bliss.That's not really how DC wants his characters to be I'd guess. Debbie and Diane have shared sexual history that even predates MC's birth. Jenny on the other hand doesn't want to share MC's dick - unless it's for profit, maybe.
As said, it's not me sayin that, it's just how DC seems view his characters.
Though like you said none of this is our decision, DC writes it the way DC writes it. I just wish we could get a Threesome with Mia and her mom, particularly since her mom is now my fuck toy.