In an erotic dream where she pushes Ume down, kisses him into silence, and rides him bareback while everyone else is asleep.
Or at least, she'll be telling herself "This must be another dream, nothing this good could happen in reality" the whole time. Afterwards Ume will be confused by the fact she's acting like nothing ever happened.
6-8 weeks later, she'll wonder why she's late.
Yes, I've turned that one-off joke about a post of "." into head-canon. 😅