Stable beverage container

A beverage container including an outer cup having an integrally formed base plate, an inner cup disposed in the outer cup, a base including a lower portion configured to releasably engage the beverage container to an external surface, the lower portion including a suction cup defining a cavity and configured to sealingly engage the beverage container with an external surface by forming a seal between the suction cup and the external surface, and a valve operably connected to the integrally formed base plate and movable between a first position and a second position to control fluid communication between atmospheric pressure and the cavity.