Shopping for Pigeon's Milk

Conversation overheard outside the supermarket
Pigeon A: What’s young Walter up to, flapping about like that?
Pigeon B: I’ve asked him to fly inside to buy some pigeon’s milk (winks), but he’s a bit worried they won’t serve him.
Pigeon A: Pigeon’s milk? But according to the OED, that’s an ‘imaginary substance which, as a joke, a child or gullible person may be sent to buy’ … Aha! … ha, ha, ha, ha, ha, ha, ha!
Pigeon B: And tomorrow, we’ll send him out for some stripy paint and hen’s teeth.
Pigeons A and B: ha, ha, ha, ha!
(Both pigeons then fall off windowsill in hysterics)

Day #37 of a 365 project, where the daily pic is informed by the OED word of the day.