How to keep a guy hard after he cums?

My boyfriend came to me and told me he wants to try cumming 3 times in a row and I’m clueless on what to do. He’s done it before with his ex, but that was over a decade now and men’s parts tend to get tired after that long 😂😂 any tips on how to keep him going for 3 rounds? We’ve done 2 rounds before but after that he doesn’t attempt more. I know guys get sensitive after they finish so I don’t want him to be in any discomfort. He loves when I give him oral and he really likes it when I’m dominant. Thanks ladies !!