itch.io

im personnally buying on itch and steam, but the best and safest overall place would be steam as of the event from payment providers doing all kinds of stuff to NSFW games on itch

cant wait to get completly dismentale by a tank

https://store.steampowered.com/app/3238940/A_Simple_Life_with_My_Unobtrusive_Sis...
https://fansaiko.com/en/product/698f5b4925da5ed586c4e87e
as far as i know there two are the alternate sides u can buy them on from the Creator, downfall is u need to wait a bit still for the steam version, but personally i wouldt worry as waiting for the full game is properly alot more rewarding in the end