My university classmate went to the army, but we can still keep in touch. It's a bit like a long-distance relationship, but the girl flirted with me and said that she wanted to find a new partner. Is there any good book that you can recommend?

My university classmate. My partner has gone to the army, but I can still keep in touch with him. It's equivalent to a long-distance relationship. The girl flirted with me and said that she wanted to change her partner. I'm a sophomore. Girl A, B, and C are roommates, and we're close. Girl C, B, is my best friend. In my freshman year, I confessed to girl A, but it's limited to confessing. Girl B's partner is a classmate from my revision. We're together in university. Girl B sometimes flirts with me, but because she confessed to girl A, she keeps her distance. This semester, A broke up with her boyfriend and invited me to dinner. Before dinner, she turned to me. At that time, B kept hinting that I knew that I had confessed to A. During dinner, B told C that he knew that I had confessed to A, but B said that he wanted to change his boyfriend. During class, I often had chicken dinner with my gay friends and B.C. asked me to sign up for an elective course. We signed up for the same course and ran together every night. B.C. asked me out first. On the first day, he asked A out. We ran together. We were just normal classmates and had no stories. I felt that A didn't like me, so I wanted to give up. On the way back to the dormitory, B.C. followed behind A and me at a distance. Later, I didn't want to ask A to run anymore. I ran with B. During this time, B said that he had quarreled with his partner. His partner was not good, but he said that I was cute and that I was better than his partner. A and I were from the same hometown and went home together during the holidays. B would also unconsciously ask what A and I were doing. Usually in school, he would ask me many times what I was doing. Later on, she would also hint that my nickname in junior high was the same as her ex-boyfriend's, and she wanted to call me by my nickname. One day, I secretly sang a song, wanting to become a planet to protect you, singing until you secretly faced me. However, the next day, on her partner's birthday, she made a video showing off her love, meaning that she was waiting for her partner to come home. What should I do? B is a lively, confident, and beautiful girl. C said that B heard that I said she was fat and didn't eat for a day. B was bold enough to say that he would not return to the dormitory after dinner. I want to ask if I like her too. What should I do?