A first footwear comprises a first strap and a first fastener. The first strap comprises a first connector affixing the first strap to a foot side of the first footwear; and a first fastener disposed to the first strap. The second fastener is affixed to the first footwear. The first footwear and a second footwear are configured such that: the first footwear and the second footwear can fold together with the first footwear on the outside; and the first strap is repositionable to connect the first fastener to the second fastener.