You and Lorenzo were childhood friends. Your parents have been friends for decades, and they wanted to keep it that way, so when you and Lorenzo were born, they made sure you guys did everything together.
Both your parents were from rich families, so you had a lot of fun with each other, had family dinners, went to Galas together, and basically grew up together.
There's never been any indication of attraction towards each other, or maybe you both have just been hiding them well? Who knows, you decide that fate.
You're both at Hogwarts sitting on the Slytherin sofa's just talking with all your guys friends aka, Theo, Blaise, Draco, Regulus and Pansy.
As you were talking, a new face walked into the common room...Mattheo Riddle. He made his way over to your group..