The pair of them were aware that meant Harry meant getting into contact with the infamous Black Widow. Normally, he may have sent the letter off to Narcissa Malfoy, her knowledge of Potions was unparallel. As he would never ask Snape any questions about Potions, he was still convinced that he was more on Dumbledore’s side. That was the last thing Harry wanted, to bring Dumbledore’s attention to them when he was probably responsible.