It starts in your own head to be honest, to be convincing at it, you need to put yourself into the kind of headspace to where you can accept this, but it can be difficult especially if you have a very solid relationship with minimal stress. I know that sounds weird, but this may be what you have to do to break the initial stress.
Think of how like method actors will put themselves totally into the role they are playing, or how a theater actor may bring up a painful memory to make themselves cry on cue. In a similar manner you will have to project the kind of attitude that he wants you to have onto him as someone deserving of it. In general a good way to start is think of him as totally unworthy of your sexual attention, that you are only using him for sexual desire, and that even then he's unable to satisfy. With each technique you can criticize it and tell him you'll have to do all the work because he isn't cutting it. Of course just spice it up with dirty talk and the "names" he may want.
This is a type of roleplay, don't consider that he's taking it literally, just as you aren't taking it literally either. It's only extreme roleplay. One of the key things to make extreme roleplay safe and enjoyable is before ever engaging in it, even in situations where you think you may never need it, come up with a safe word, something random like "Apricot" or some word you know you'd never say in a normal sexual encounter. That way if things get too awkward or go beyond your limits, you can stop, and talk through it, and come up with a solution.
Just remember that it's just play acting, and in THAT type of play acting you normally are throwing out all the rules for typical appropriate sexual conduct and pretending to be mean, rude, ungrateful, narcissistic, and even cruel. Don't worry though, it's all in fun, and while I've never myself cared to try this, I've heard among those in that lifestyle, they greatly enjoy it.