one can not be a sandy vagina, one can only have a sandy vagina. this term is used to describe someone who is complaining about slightly uncomfortable situations. if a women is complaining about anything, she is said to have sand in her vag. If a man is complaining, he has now lost his penis, developed a vag. and has sand packed inside of himself, also the name sandy can be used for nick name, once the sandy vagina term is accepted by your click!
To have sand (literally or metaphorically) stuck in your nether regions. Remember that time you were at the beach, and your bikini bottom slipped as you fell into the sand, and all those little pieces got stuck in your lady parts? Remember how miserable and bitchy you were? Remember that stupid cow from work, how she complained non-stop about stupid things, and got offended over every little comment? She had "sand in her taco." It was almost as if she had fallen into the sand and was miserable the rest of the day.