Modular beverage container system

A multimodal container selectively, alternatively, and repeatably reconfigurable between a cup mode and a bottle mode, comprising:

• an outer shell having a closed base, a top, and a first wall coupled to said base and extending to said top, said first wall defining a first cavity having a first volume and a first cavity opening into said first volume generally opposite of said base at said top, a portion of a first periphery of said first wall at said top including a first closure structure;
• an inner shell having first end, a second end, and a second wall extending from said first end to said second end defining a second cavity having a second volume and a second cavity opening at said first end, a portion of a second periphery of said second wall at said first end including a second closure structure;
• and
• a coupler engaging and sealing both said shells proximate said first cavity opening and said second cavity opening in both the cup mode and the bottle mode, said coupler including a first portion having a third closure structure complementary to said first closure structure and including a second portion having a fourth closure structure complementary to said second closure structure;
• wherein the cup mode includes said first cavity opening proximate said second cavity opening with said inner shell nested within said outer shell and said second end extending towards said base;
• and
• wherein the bottle mode includes said first cavity opening proximate said second cavity opening with said second end extending away from said base.