Well, what the fuck did you expect with a post like that? For all anybody knows, you're trying to run it in 8k on a fucking ZX-81.
Atleast add some details when asking for help, like what GPU, CPU, amount of RAM, what system do you run, what version of the game do you play? What screen resolution do you use? Did you install any mods? Basic stuff like that.
I tested v0.10.4e on a potato PC, i5-3150p(!!) GTX 1650 and 16GB RAM on Win10 in 1920x1080 and I have no slowdowns with cum. That CPU is so old, they don't even have it listed on cpu.userbenchmark anymore! Granted, the game only runs at 25-30 FPS, but there is no slow-downs with cum, unless I really go bukkake on them.
I also tested it on a Ryzen 5 5500, Radeon RX 6600 and 16GB RAM on Win11 in 1920x1080, and on that I get stable 60 FPS, I capped the frames to 60, because that's what my screens refresh-rate is. Minor slow-downs when they are drenched in cum, between 50-55 FPS. Not really potato PC, but still not great.
Also, this is a game, made by ONE! guy, so don't expect AAA game optimized performance. It's not gonna happen. Shit, maybe you even need some NASA level PC, if you want to avoid 'bukkake' slow-downs.
I'm sorry I went off on you like that, but it just annoys the shit out of me when people asking for help, don't even add basic stuff.
"Help people help you"
Btw. I liked the girl you posted on the other thread, Tisa Caoili.. Nice one.