I don't think they really had any dialog, except for some moaning as they got frisky on the altar. It seems like they could have had some dialog, to elucidate the significance of their boinking. Although, maybe it was significant enough that Isaac called it fertilization, implying that they were trying to emulate the corn itself, possibly?

Anyway, it helped to give some more details to the weird little culture that they had developed, isolated for over a decade. out amongst the cornstalks.

Were they, the couple on the altar, the people called oldest boy and ponytail girl in the cast list?