This was in the Annini's Gifts tribe. Snowblood found the infertile Issira and they fell in love, but they could not have children because Issira was infertile. She wasn't let in, either, since we couldn't have many creatures and she didn't have many abilities.
I know, I wasn't supposed to see the genes, but since her stats showed she was infertile, i thought 'might as well look since she's never gonna breed'.