Correct me if I'm wrong: but what i understand what defines a "bull" is a male who has a consistent intimate relationship with a married women rather it be just dating or it's just sexual. Just by that definition alone, size is irrelevant. What matters here is does the married woman prefer that man to be the one who provides her the needs she searching for. Doesn't matter if he's 5 inches or 9+. If he gets the job done and she wants it consistent with the consent of her significant other, then by definition that is her bull.