Beverage Container

A container comprising:

• a first vessel including a lower surface, an upper end distal to the lower surface, and a first vessel wall extending from the upper end to the lower surface, the upper end, lower end, and first vessel wall defining a first internal volume of the first vessel, the upper end defining a first opening through which a substance may enter the first internal volume;
• a second vessel including a lower end, an upper end distal to the lower end, and a second vessel wall extending from the upper end to the lower end, the upper end, lower end, and second vessel wall defining a second internal volume of the second vessel, the lower end defining an opening through which a substance may exit the internal volume of the second vessel, the second vessel including an attachment interface that detachably connects to the upper end of the first vessel;
• a cap secured to the upper end of the second vessel;
• and
• a seal removably-secured to the lower end of the second vessel, the seal being sized and shaped to cover the second opening and create a barrier preventing fluid-flow communication through the second opening, the seal including a tether that is attached to the cap;
• wherein the cap, the seal, and the tether are adapted to (a) allow the seal to remain secured to the lower end of the second vessel when the cap is in a first position at the upper end of the second vessel and (b) cause the seal to at least partially separate from the lower end of the second vessel when the cap is moved to a second position.