A large pouch adjacent to (or in front of) a woman's stomach that holds cum. Can have the effect of making a woman look slightly pregnant and confusing others.
Not easily recognizable, sometimes mistaken for an alien fetus or an unborn child, leading to awkward and/or disparaging remarks.
However, continued observation (9+ months) can rule out the latter, as the woman obviously isn't giving birth.
Michael: Check out the cum pouch on that girl over there!
Ashley: Jeez, man! I thought she was preggers!
Marie: You guys are SO wrong. That is such an alien fetus.
All three together: Well, which is it? *they ponder*