A drink container, comprising: a container body having an inner body portion defining an interior fluid passageway with an upper end opening (30, 230); and a lid sized to permit insertion into and removal from the fluid passageway through the upper end opening (30, 230), the lid having: an upper member positioned within the fluid passageway and having a drink dispensing aperture; a lower member positioned within the fluid passageway in position below the upper member; a seal having a flexible perimeter seal wall, the seal having an upper end portion attached to the upper member and a lower end portion attached to the lower member; and an actuator member movable to first and second operational positions, as the actuator member is moved to the first operational position, the actuator member moves the lower member to a first position below the upper member and sufficiently flexes the perimeter seal wall so that the perimeter seal wall moves laterally outward into fluid-tight sealing engagement with the inner body portion, and as the actuator member is moved to the second operational position, the actuator member moves the lower member to a second position below the upper member and sufficiently flexes the perimeter seal wall so that the perimeter seal wall moves laterally outward into engagement with the inner body portion to inhibit removal of the lid from the fluid passageway if moved upward toward the upper end opening (30, 230), but not sufficiently laterally outward to place the perimeter seal wall in fluid-tight sealing engagement with the inner body portion, the lower member being positioned farther below the upper member when in the second position than in the first position, and when the actuator member moves the perimeter seal wall to the first position in fluid-tight sealing engagement with the inner body portion, drink in the container body below the upper member is prevented from being dispensed through the drink dispensing aperture when the container body is tilted. a container body having an inner body portion defining an interior fluid passageway with an upper end opening (30, 230); and a lid sized to permit insertion into and removal from the fluid passageway through the upper end opening (30, 230), the lid having: an upper member positioned within the fluid passageway and having a drink dispensing aperture; a lower member positioned within the fluid passageway in position below the upper member; a seal having a flexible perimeter seal wall, the seal having an upper end portion attached to the upper member and a lower end portion attached to the lower member; and an actuator member movable to first and second operational positions, as the actuator member is moved to the first operational position, the actuator member moves the lower member to a first position below the upper member and sufficiently flexes the perimeter seal wall so that the perimeter seal wall moves laterally outward into fluid-tight sealing engagement with the inner body portion, and as the actuator member is moved to the second operational position, the actuator member moves the lower member to a second position below the upper member and sufficiently flexes the perimeter seal wall so that the perimeter seal wall moves laterally outward into engagement with the inner body portion to inhibit removal of the lid from the fluid passageway if moved upward toward the upper end opening (30, 230), but not sufficiently laterally outward to place the perimeter seal wall in fluid-tight sealing engagement with the inner body portion, the lower member being positioned farther below the upper member when in the second position than in the first position, and when the actuator member moves the perimeter seal wall to the first position in fluid-tight sealing engagement with the inner body portion, drink in the container body below the upper member is prevented from being dispensed through the drink dispensing aperture when the container body is tilted. an upper member positioned within the fluid passageway and having a drink dispensing aperture; a lower member positioned within the fluid passageway in position below the upper member; a seal having a flexible perimeter seal wall, the seal having an upper end portion attached to the upper member and a lower end portion attached to the lower member; and an actuator member movable to first and second operational positions, as the actuator member is moved to the first operational position, the actuator member moves the lower member to a first position below the upper member and sufficiently flexes the perimeter seal wall so that the perimeter seal wall moves laterally outward into fluid-tight sealing engagement with the inner body portion, and as the actuator member is moved to the second operational position, the actuator member moves the lower member to a second position below the upper member and sufficiently flexes the perimeter seal wall so that the perimeter seal wall moves laterally outward into engagement with the inner body portion to inhibit removal of the lid from the fluid passageway if moved upward toward the upper end opening (30, 230), but not sufficiently laterally outward to place the perimeter seal wall in fluid-tight sealing engagement with the inner body portion, the lower member being positioned farther below the upper member when in the second position than in the first position, and when the actuator member moves the perimeter seal wall to the first position in fluid-tight sealing engagement with the inner body portion, drink in the container body below the upper member is prevented from being dispensed through the drink dispensing aperture when the container body is tilted.