What does this word mean?

Ok so I went to a festival that was here in my town and there was this famous movie acter there signing pictures and taking pictures with fans and anyways my brother n law took a picture with that famous guy and he's Mexican and he signed on the picture my bro n laws name and he put "p the wire foo" now my question is what the heck does p the wire mean in Mexican terms?! I seen a few Mexican movies that use that term but I have no idea wat it means?