I would recommend that you include the context in questions like these. This was from the (quite excellent) movie The Bucket List. A is Jack Nicholson's character, and B is Morgan Freeman's character. (I can't remember the characters' names, so I'll just use the actors' ones.) They are racing cars around a racetrack. Nicholson starts (jokingly) criticising Freeman's driving, to which Freeman replies that Nicholson is looking to get a beating in their race. At this point the dialog starts. Nicholson: "You got nothing! Ha Ha" (Translation: You don't have the skill to beat me.) Freeman: "Got enough for you, Sunny Jim". (Translation: He has enough skill to beat Nicholson in a race. "Sunny Jim" is just a name that Freeman calls Nicholson as a put down, but an affectionate one. It's playful banter.) At that point Freeman calls out "Dangling" and puts his foot on the accelerator. Now I will admit that if anyone said that to me, I would reply with "What on earth are you talking about", but it's clear that the scriptwriter did have something in mind from the next line of dialog. Nicholson catches up to him and yells "Did you just make a penis reference?" In the mind of the scriptwriter he did; the use of the word "Dangling" suggesting that Nicholson was impotent. (Or more precisely that his driving was impotent. It was an analogy.) The key thing to take away from this is that there is hardly anyone on earth who would use those particular lines of dialog in that way. I think that the writers just wanted to avoid using the somewhat cruder language that two friendly but competitive guys might use to each other. There is no great language lesson to be learnt here; I think it was just a bad moment of writing in what was on balance a very good movie.

A: You got nothing! -- Ha, ha. B: Got enough for you, Sunny Jim, dangling. (who is the subject of "dangling"? Sunny Jim?) A: Did you just make a penis reference? (what is the meaning of this sentence? is there any relation about "penis" and" dangling"? the penis is dangling?) B: What if I did? Yes, I think they are making a play on words (double meaning) to be sarcastic or insulting. You got nothing => Your penis is small and useless. Got enough for you => My penis is big enough to satisfy you. Dangling => limp dick; impotent; cannot get erect (otherwise, it would be "Sunny Jim, Darling")