see (one) coming

see (one) coming

To view someone as being particularly gullible and thus easy to deceive, swindle, or exploit. The guys in that shop must have seen me coming, because they convinced me to buy the most expensive stuff they had. I can't believe they managed to sell you such a piece of junk. I bet they saw you coming a mile away.
See also: coming, see
Farlex Dictionary of Idioms.

They must have seen you coming.

You were really cheated. They saw you coming and decided they could cheat you easily. Andy: It cost two hundred dollars. Rachel: You paid two hundred dollars for that thing? Boy, they must have seen you coming. Bob: Do you think I paid too much for this car? It's not as good as I thought it was. Tom: It's almost a wreck. They must have seen you coming.
See also: coming, have, must, seen
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

see someone coming

recognize a person who can be fooled or deceived. informal
See also: coming, see, someone
Farlex Partner Idioms Dictionary

see somebody ˈcoming

(informal) know that somebody is innocent or stupid and decide to lie to them or cheat them: ‘I paid €500 for it, and it doesn’t work!’ ‘They must have seen you coming.’
See also: coming, see, somebody
Farlex Partner Idioms Dictionary
See also:
  • see somebody coming
  • see someone coming
  • They must have seen you coming
  • easy game
  • easy meat
  • sucker (one) in
  • put a con on someone