During a threesome, when the 2 males ejaculate inside the female at the same time, one in her ass and one in her vagina, she then farts and makes 2 bubbles simultaneously
A Double Bubble is when a bra circumference is too small for a woman to wear. Instead of overflowing over the top, the elastic band around the bottom slips up, causing each breast to appear as 2, or 4 breasts.