Spying
Many vampires had weird habits, most likely because they were in the dark most of the time. Others started showing strange behaviour after being stuck inside for a long time to avoid the sun. These thoughts were going through Fex's mind as he was looking at Quinn.
Fex himself was also considered as weird by his fellow vampires because he showed so much interest in humans. However, so far, his experiences with humans hadn't been that great. No one would talk to him, and all the other interactions he had with them was him getting attacked. First, it was Erin in the library, then his two roommates, and also Peter and Quinn had assaulted him in the forest.
Finally, when the female student's leg had fully healed, Peter no longer felt weird about eating the limb in front of him. Now that she had both of her legs again, it didn't feel like he was eating a part of her anymore. So without further ado, he started eating. It would be a shame to let fresh meat go to waste.