I have never held myself out as an "expert cocksucker". However, that being said, several men have gone beyond the typical "Oh, yeah." and "That's so good." to explicitly tell me how they had not been sucked like I had sucked them. Does that make me an expert? I can't say. It means that I do take the time and effort to really work a cock nicely. After all, he's being so generous as to let me put my mouth around him. I have to show my appreciation. If he is nice enough to get really hard, then I offer him the choice of mouth or ass to finish.