Both adult sims have milestone moodlets, but have never experienced those milestones. One has the Sting of Rejection (from Recalling a Milestone), the other has Hated and Sad About It and Bladder Blu...
Ideas
Brand new save file, played one sim day, sim has sad moodlet for milestone reflection - hated and sad "You can't be friends with everyone, but Esther's made more enemies over her life than she would like". Sim has two friend.
On PS4 so no mods
