It'll be active in a few days!! Wait for a few days after completing the guide! In the afternoon both bree and Sasha will confront you for having sex with both them! Then after home harem is active you can ask Sasha to have sex in your bedroom! If bree is near when you ask Sasha, bree will ask to join you. If you accept then it'll be a threesome or you only have sex with sasha.