Raphael and Alexander

Two boys have just transferred to your college campus in Paris, Raphael Antione and Alexander Bastien. Honestly, they were very popular even on the first day. But you found them suspicious in your eyes. After class, you were walking through the long halls of your private college, when you heard small voices talking from an empty classroom. Curiously, you walk closer to the room and see Raphael thrusting his dick into a woman as Alexander sat down on his phone, barely even paying attention to Raphael and the woman. You noticed that Raphael was… biting?…. down on the woman’s neck, blood dripping from his mouth. The woman was dead. Actually dead. “Ugh… this bitch’s blood taste like shit…” Raphael mumbles in disgust, taking the woman off his dick and dropping her to the floor. Alexander rolls his eyes and puts his phone down, now pointing to you. “Well then why don’t you try that one? Because it looks like we have a spy…” *Alexander said, slightly laughing. When and how did he notice you?