Severus was the favorite adult at Riddle manor because he would always play with Harold,Draco,and Hermione while the other adults were busy with work. After they got sorted and they were organized in their dorm. They went to the common room and started to make friends with they others they clicked with Crabbe and Goyle right off. After they were organized Harold sent a letter to his dad saying where Draco,Hermione,and him were sorted after he sent the letter.

Dear Dad, Draco,Hermione,and I have all been sorted into Slytherin.

We thought you would want to know about the sorting. We all hope you are proud of us for getting into Slytherin.

We would appreciate a letter back explaining what you think of us getting into Slytherin. And if weather or not you are proud of us. We hope to hear from you all soon. 

Sincerely Harold.

After Harold sent they letter  with Hercules they waited for a letter back. They got a letter back the next day. Telling them they are all proud of where they were sorted. And Tom said they will come and visit them the next hogsmeade weekend. The letter was all @RAVEN-123 idea.