Skills to get the guy off? Has absolutely nothing to do with that. I think there's been numerous threads on here over the years about how extremely difficult it is for the male talent in porn. It isn't about banging some hot chick while the camera happens to be rolling and oh, she's sooo good that he's going to cum and the camera dudes are just happening to catch it all. Each guy has his own way of being able to perform and do what he needs to do during the scene, I'm not even going to go in to some of their tricks and things I've seen or what some talent has told me that they have to think about to cum. They go to their own place in their mind while sometimes having sex in a very uncomfortable and awkward position with a chick who may not have said two words to him all day..or doesn't even like him or isn't attracted to him. Or he might not be attracted to her. Or she didn't shower and she smells, her asshole is hairy, she's just a bitch, she's annoying...the different variables are endless. All of this while people are literally STARING at your wood, discussing it and asking you if you're fully hard and ready to go...and oh wait, it's only semi hard now, hurry up and get it back so we can keep going. And while you're getting hard again maybe the female talent is back on her cell phone or staring at the ceiling...she might help you out but maybe not,
You Might not even want her to if you don't like her. And then you have to cum when it's time to cum and you do whatever you need to do to get you there. That's the reality of it. I've been on set before when one of the bigger name male talent couldn't stay hard, it wasn't during my scene but everyone was aware of it and it set us back hours b/c they had to call in someone else. If he wasn't who he was, he probably wouldn't have gotten more bookings after that.