when someone pimps young guys to older gay guys in order to extort money from the dirtyolder man who is probably rich and desperate enough to pay top dollar for a young pony...hence pushing ponies.
in todays world with recession problems and people having shortages in money, the money to be made on pimping isnt with high maintenance women that you are trying to pimp to middle or lower class johns. The real money is in pimping boys to older white collar gay men that are married or recently divorced and usually have plenty of money to spend and are desperate enough to throw down top dollar...thus pushing ponies
Its a great slang phrase that can be used to describe a variety of situations
Chad: "Yooo Jimmy was Pushing 🅿️ at the barn today, no way he can come play in COD"
Jimmy *breaks into the house, soaked in sheep cum* "Yoooooo wassup today was another day of the grind."