The "Swallow This" series is what you're looking for, but you need to start with the earlier releases. The later ones, while still good, don't feature Peter as the "sperm vendor" in a majority of the scenes.
Also, the "Deep Throat This" series did all swallowing releases on #16, #20, and #24, and I think some more recent releases, too, but #16 and #20 are the best, by far. #16 has a Peter North/Brianna Blaze scene that is one of my favorites of any in the entire "Deep Throat This" series. #20 has some incredible 3-on-1 mini-blowbangs that include Peter North, with Arnold Schwarzenpecker and Johnny Fender (all 3 of these guys usually deliver monster loads). Amber Simpson and RayVeness in particular, get incredibly full mouths of sperm and chug it all down in one gulp. Awesome!

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