Hot pink, searing turquoise, kelly green, sunrise orange. The foam eye candy of flip-flops is so visually delicious that digesting the reality of owning a pair, for $5.99 or less, leads to a flickering sense of freedom -- a gateway scented with a hint of coconut oil.

But that thong strap is wicked. It tries to divide the foot in half, choking the tissue between the big toe and second phalange and pressing into the layers of flesh that stand between it and the fork in the common plantar digital nerves. The pressure hurts. Metatarsal bones ache, and blisters form. Foot doctors warn of the sandals’ arch problem, the curling toes and the safety hazards of wearing them, but they don’t tell us about the flip-flop duality, between the promise of summer and the treachery of thong sandals.