Kind of like taking a poop. Absolutely way better after you get used to it.

[Meeting that eye and saying it all 100% seriously, even if the part about pooping could have been a joke, Oikawa kisses softly at his chin.] But if you'd really rather not, I like what we do already. [The words are softer, gentle with asking overall - he knows Iwaizumi still doesn't get why he likes sex when his dick has to go up his butt, why it feels so good.]