If you mean exclusive to one girl, then I haven't decided that yet, but it could be a possibility. If so, it would heavily depend on the choices that you make throughout the game.
Exclusive end-game relationships aside, I do plan on including a lot of lesbian content. I'm hopeful that I can include this as an optional thing that only unlocks after you get kinky with Kendra. Meaning the 8 other girls you'll be able to do that with, won't be an option unless Sienna's already accepted sex from Kendra.