Sucking Dick?

Ok so this has been a mystery to me for the longest time. Across multiple porn sites there are videos of guys blowing hot guys with big dicks constantly. I'm aware that porn is not realistic. Even the "amateur" sites. However, I still want to know how a guy can get between the legs of that many guys. I'm not in the closet at all so I just want to know how I can make it more clear that I'm down to suck dick? Lol. Do I just start asking.TL;DR: I have a bit of an oral fixation and I want to suck dick more frequently. So do I just ask the guys that I want or is there a secret method that I don't know about lol.