Oikawa visits Iwaizumi at home when he's sick:

Oikawa:
omy what great big arms you have iwa channnnn

What great thiCc tHighs yOu have iwa channnnnn

oMIGIOSH WHAT NICE CALVES YOU HAVE IWA CHANNNN

r u really my iwa chan??????

Iwaizumi: shut up trashykawa I'm sick and I'm not your grandpa

Oikawa: no you're my grand DaDdY

When u dAdDy is the grandest of them all