He didn't believe you when you first confessed to him, no one liked him they liked Oikawa. Sometime later you two started dating. Iwaizumi loves showing you off, especially to Oikawa. Over time you also became friends with Oikawa.

You were all hanging out in an empty classroom for lunch. Oikawa was going on about some new fans he has or volleyball, Iwaizumi pulled you onto a desk, sitting in front of you holding your waist.

"Want to watch us practice?"

He whispered holding you close to him.