Tim Riddle.

They never got along, on the contrary, they hated each other. One day while arguing in potions class, they broke a very important and expensive artifact. Snape clearly punished them, but he couldn't have chosen a worse punishment than making them clean the entire classroom and bathrooms together. In addition to having to work in pairs, they had to help the first year children, a nightmare for you and Tom. Tom said he could pay someone else to do it, but Snape didn't accept bribes of any kind, leaving him with no options, it was definitive. And that's how their big mistake led them to work together.