A viral clip claims Shake Shack quietly bumps up item prices when you decline to tip, and it's bad for customers already fed up with tipping everywhere.

• A customer filmed ordering shakes, then declining to tip — and every item jumped 50 cents at checkout.
• The gripe is that big chains lean on tips so they can pay workers less, then pocket more when customers tip anyway.
• Tipping fatigue is spreading, with prompts now showing up everywhere from coffee counters to plumbers.
• The frustration is less about one chain and more about who really benefits when a tip is added.

Outlook: Expect more customer pushback and scrutiny of "tip or pay more" checkout tactics at fast-food chains.