Very urgent!!! Can anybody give me some advice?!?

I just moved to a new school in November and became friends with this one boy in my cl. I realized that I have a crush on him. Well yesterday on our way to science cl we were lined up outside the room we go to for science and he started smiling and bouncing. He said: "Im soooo happy!!!" I asked why and he said it's cuz of Valentines Day. Again I asked why and he said it's cuz he has a girlfriend. I felt a cold shock go through my stomach and said: "Oh, cool" and then we went into the clroom. I talked to him again this morning cuz science was right before we go home. Anyway he started bouncing again this morning and said: "You know why I'm so happy?!?" I told him: "Yes, you told me yesterday." he forgot that he told me and went "I did? Oh yeaaaah I remember." We were talking again after recess and he said that he wanted to kill this one girl and when I asked why he told me: "She makes fun of me and __ ( second girl )" I asked what the second girl had to do with this and he said: "Oh, well she's my girlfriend." another cold shock went through my stomach. This time I was kinda cool with it tho. cuz I knew the girl and she's sweet, kind, funny, pretty. A. K. A. Just about perfect for him. I was glad he wasn't lying and later when I saw her in the hall I was mad. I was thinking about maybe buying him a carnation from the school's flower sale, should I do that? What do I do to get over him? Should I wait for them to break up? What do I do?!?