The next time we see Sora, she's having sex with Selia. She's not having sex because she wants sex, she wants to be in Selia's arms. She wants to feel her body's "itching" . But Selia isn't having sex for the same reason that Selia is having sex: she wants her body to feel "uneasy" for the first time in a long time. Selia doesn't know what to do, so she'll just have to relax.