"FRED AND GEORGE WEASLEY!" Molly Weasley yelled for what felt like the millionth time in her life.
"I didn't do it." the twins said in unison, walking in the room and not blinking an eye at their mother's fury. This happened way too often for them to be afraid any more
"An owl just showed up, can you guess what it was carrying?" the twins gulped, this was worse than they thought. They had a good idea what the owl brought, but they hoped they were wrong for the sake of their lives. "The owl was carrying OWL results, very atrocious OWL results." she shoved the results into their faces. "Would you care to explain to me why these results have your names on them?" by now she was speaking in a deadly calm voice, "Because i know no sons of mine would ever do this badly!". The twins didn't know how to respond. They knew the only explanation they had would make her angrier. So the twins did what they always did in uncomfortable situations, they made a joke.
"Well mother it appears Hogwarts has made a mistake-" Fred started
"These results are much too good to be ours!" George grinned
"Honestly, to get these grades we'd have had to actually show up to the exams!" Fred finished identical grins on their faces.
Molly couldn't get out a full sentence she was so angry; "Room now...grounded...rest of the summer". The twins left without arguing, knowing better than to test their mother at the moment. Besides everything they needed was in their room.
The twins knew perfectly well why they did so poorly. In fact they didn't actually think they did badly at all. They might have only gotten three owls but they were all outstanding. They knew they could have done just as well on their other exams, but those just weren't important. Not for what they planned to do after school. You don't need history of magic, or divination, or transfiguration, not when what you planned to do was start up your own joke shop. After all wasn't the point of OWLS to show you what you were good at, to help you decide what you wanted to do after school? The twins knew exactly what they wanted to do and in their opinion they were well prepared.