Massive respect for Tama-chan for managing to explain like that in a single setting, as well as being under pressure (both public and urinal-wise) while explaining it.
The power of a seme. Explaining what mating is in full view of everyone in Comiket. Even the circle person beside them jumped in to help when they were too engrossed.
@HiiragiIzumi
The title says she was let in afterwards...