The group may have been in public at the moment, but Eb and this colt had not been quiet last night. As much as Honour was glad to not be hung over this morning, a little booze might've actually allowed her to sleep through her own frustrations -- and her neighbour's noisy emanations. Sparkshower shared the other wall with the sergeant, so she must've heard every grunt and moan, too. Maybe that's why she took off somewhere early that morning before anypony else woke up.