Two indentions located on the small of a woman's lower back, located on both sides of her backbone. These indentations can be used to temporarily contain ejaculation in a pocket like fashion. This is found quite useful during "doggie style" sexual intercourse as a place to hold semen.
Last night I was nailing that broad doggie style, when I pulled out and I shot my load right into her cum pockets on her back! It was awesome! Not even one drop spilt!