
but why is the redhead mad in the first place I literally don't care about her and when she's jealous it just annoys me. Leave mc alone ヽ(`Д´)ノ

Ive said this in my previois comment, i think the author pulled that jealousy quite early and didn't give the red head her back story. Since its the same with a fic ive read i'll relate her to that character and say it's probably years of feeling that the guy prioritizes fl, them sharing a lot of memories she isnt included and her thinking that her memories with the guy could never compete to that. Also probably hearing those two look good together which fl and guy would only smile about and never deny.
omg I was worried why they were blushing with each other but it's understandable