In the lunchroom. Because it's quiet. It was a great place to eat, though. I'm glad you enjoyed it. You can look at three different scenes from three different filmmakers of just a blowjob, and you will see three different techniques.
Camera work is first.
Casting it right and having attractive people is important, but knowing how to shoot them is your primary subject. That is the most important to me. And lighting is important. Because you want to make it look seductive, but yet, you want to be able to see every crack and cranny. And every suck and fuck.