Pushups with Iwaizumi and Oikawa

We all know Iwaizumi has amazing arms, but what happens in the process of getting them? This might've been done before but it's based off a head cannon I found on Pinterest: https://pin.it/4RBtyg6!

(https://twitter.com/aunnnn1330/status/1327754036318138368?s=12) Credit to the original artist that made this cover!