An arrangement of two or more females riding in tandem in which the ass of the front girl is pressed against the vagina of the other. This usually occurs between two fully clothed females riding together on things such as horses, motorcycles, scooters, and jet skis. Not to be confused with "nuts to butts" which describes the same arrangement but occurring with dudes.
"Did you see those lesbians ride by on those motorcycles? They were all riding poots to coots."
"Her horse died on the trail so we had to ride poot to coot all the way home"