A security device for a double door, including a first locking portion having a curved portion and an elongated male portion, and a second locking portion having a curved portion and an elongated female portion. A lock mechanism includes a pair of rows of teeth having a gap therebetween and associated with the bottom side of the male portion and a locking prong mounted to the female portion. The locking prong has a flexible finger portion that terminates in a T-shaped end. The finger portion can slide between the gap in the rows of teeth. A release button mounted on the female portion, when pressed, causes the locking prong to bend downward, disengaging the T-shaped end from between the teeth and allowing the first and second locking portions to separate, thereby unlocking the security device.