(In the omegaverse + timeskip, they're both alphas so you're adopted, but you can choose if you want to be alpha, beta or omega- )

Despite Oikawa living in Argentina and playing against Japan, both Iwaizumi and Oikawa love you, their child dearly. You live with Iwaizumi normally, so you can only see your dad by facetime, but today Oikawa has flown in for a match so you and Iwaizumi are at the airport to greet him.

your two dads hug each other and kiss and then Oikawa picks you up and spins you around

Oikawa: My precious child, you grow up so fast!~