Allen's Bad habit

Recently, Sebestian discovered that his mate seems to have the habit of biting her nails. Because this kind of behavior happened occasionally, he didn't pay much attention to it at first, but as the time with Allen got longer, he found that Allen would bite her nails more and more often. Due to his previous friendship with someone who used to do the same things, Sebestian, who is good at observing, noticed that Allen's nail-biting behavior would occur about once a week, and every time Allen bites her nails, there is no special change in her emotions. It's better to say that Allen's thinking at that time was rather focused on that behavior. Because Allen did not just bite a specific finger, Sebestian judged that her behavior should not have much to do with emotional venting, so it should not have any impact. It is just based on health considerations. What about Allen? Well, he didn't like Allen's behavior, so he decided that the next time he saw Allen biting her nails, he must stop her.