The Night at the Museum star has been involved with Chow since 2007 but has never spoken publicly about the couple's relationship.
Now he has let slip one of the advantages of their romance - he gets money off meals at her dad Michael's swanky Chinese restaurant chain, Mr Chow.
Coogan tells Britain's Observer magazine, "The most expensive meal I've ever had would probably be at Mr Chow's in New York. Very expensive, but very tasty. I'm in a relationship with his daughter China now. I'm not talking about it. But it does mean I get a discount."