Lyric discussion by SmellyJim 

Cover art for 3 Legs lyrics by Paul McCartney

Paul is feeling insecure. He wonders if his lover will keep on loving him. He's seeing an ominous 3 legged dog. It can't run (because you need all four Beatles for a healthy dog). He feels betrayed by a past friendship and it's making him insecure about the future because he doesn't want to be hurt again. the dog appears more and more as the inevitable confrontation with his past friends comes closer. I haven't got the 3 legged fly thing but I think he's saying that he's got a one legged fly (yeah, is that a Liverpool insult or something?). Then he's flying because that's a Paul trope mostly about his success. He's daring them to knock him down. Goading them even. Very bold, he's talking down to the dog that can't run. He launches his lawsuit just before this album is released.

My Interpretation