How was it that she was having fun tossing little innocent gnomes over a fence which might potentially cause unjust harm, pain, and suffering?
She, Hermione Granger, who tirelessly fought for the rights of House-Elves and other downtrodden creatures, was here thoroughly enjoying the pain of these tiny defenseless creatures?
Well to be quite honest, if anyone else had been in her position, with Fred's strong arms wrapped around her, and his hand lightly caressing her arm just so, showing her exactly how to toss gnomes right out of the yard at precisely the right angle…they might have forgotten they had any morals too.