An Irish expression, meaning that someone is not quite with it, ie: in all probability, insane. For example, " Hey Mike, see that guy over there drinking the hot whisky? Yeah, why? Well I think he's away with the fairies. Gee John, what gave it away, the fact that he's reading his newspaper upside-down, or that he's also having a conversation with his beermat?! "

This phrase does not mean that the subject has embraced homosexuality, as may appear at first glance.

And you thought France only had faux amis.