Walburga does not often enter her younger brother's dormitory, but she has extremely important news to share from Father.
If Tom Riddle just so happens to be sitting on his bed as well, then it is just a lucky time to come. She would never admit it, especially not to Alphard, but despite his murky bloodline, he is the cutest boy in their year.
The twelve-year-old girl has decided that the quiet Slytherin is going to be her crush, and she has warned off almost all of the girls in first year. She just does not want her brother to know, because he might tell Father.
Tom catches her eye as she glances over at him from her whispering conversation with Alphard. She blushes and looks back to her brother, uncharacteristic for the usually brash girl.
It takes him a few days to come to the conclusion that the pureblood must like him, because for all his intelligence he is still a boy with no experience with girls except for his mother and the servants (and those street girls, but they will not be telling anyone).
He makes a point to smile at the girl at breakfast the next day, the veritable picture of innocence except for his flashing eyes. He notes with an absent sort of satisfaction that an almost violent red creeps up her neck. Alphard may not be the boy's friend, but he knows something is going through that scary mind of his, and it cannot be anything good.
He pulls his sister aside later that day to warn her against his roommate, but she just laughs at him and claims that she will do what she wishes and he is just jealous.
A little smirk pulls at the edge of Tom's stoic mask for the rest of the week.