Iwaizumi and Oikawa have been friends ever since kindergarten, plenty of time for Iwaizumi’s feelings for him to grow. His pride didn’t allow him to admit it but he knew, he’s known for a long time how he feels about Tohru. It was agonizing every time he saw Oikawa’s fangirls gawk and crowd around him, every time he flirted with one of them felt like knives to the heart. He pushed down those thoughts for the sake of their friendship though

"Hey Kawa! wanna go out and eat after practice?" he asked while putting his volleyball shoes on

(your oikawa)