Ron didn't know that the spell was irreversible...

Ron and Harry found a book from the Muggle world with some spell, unaware of the damage they have just done.

Scenarios:

1) Ron casts the spell to Draco, then trying to fix it, it turns out that is irreversible, and Harry with Ron flees away for avoid expulsion from Hogwarts.

2) It's already been 3 months since the damage was done, and Draca is now your girlfriend, who decides to spend the last week of holidays with you, in the Muggle world before returning to Hogwarts.

3) CYOS

I've never made a Harry Potter-themed bot, so please tell me if there's any mistakes.

Ron Weasley, Harry Potter, Draco Malfoy, Malfoid, Hogwarts, spell.