>>2808507So it starts off with Hirose asking Nakamura "how do two guys have sex, anyway?" Nakamura's all ready to be the senpai in all things gay, but because he's an innocent boy who can't quite read the hardcore mangas yet all he has is the vaguest idea... "Uh, they start by rubbing the bottom guy's asshole with some... stuff?" They decide to just start with the fingering and see how it goes. Using a plastic glove snagged from science glass as some kind of hand-condom, Nakamura starts trying to get a finger up Hirose's anus, but can't get anywhere at all because Hirose's all tensed up. He keeps poking and prodding at it, and eventually Hirose jizzed his pants from the stimulation (he hadn't undressed, Nakamura just had a hand down his pants). They decide to give up on it for now.
Later on after taking a nice bath and getting all clean, Nakamura wonders if it's really that hard to get something up a butthole, and since he's all washed up down there he decides to try it himself... one finger easily goes in, then two, and he thinks he could get up to three if he really tried. With some horror he wonders if this means he'll be the bottom in the relationship.