She’s British. She calls the spanking she just received a hiding. She calls the target area her bum. (Her fanny is her pussy.) She calls the washcloth she’s using a flannel. The bathroom she occupies is a loo.
She just discovered that a wet flannel does nothing to alleviate the the pain and humiliation of a stern hiding on her bum. But under the steaming hot water of the shower in her loo, she discovers that the hiding has excited her fanny like nothing she’s ever experienced. She gives up trying to diminish the uncomfortable feelings in her bum, and fervently starts maximizing the pleasurable feelings in her fanny, and in just a matter of moments, the latter has totally obliterated the former. Masturbation is masturbation the world over, and, thankfully, transcends semantics.