For me it was few pirated hentai games i got from my friend. And for the longest time hentai games were the only ones i played, but at some point i found western porn games and found that there's good ones among them also.
For me, it all started when my aunt took me to her workplace and left me alone with the computers. I was pretty young, and they had internet access. Out of curiosity, I searched for Dragon Ball games, and when I clicked on an ad, it redirected me to a page with Dragon Ball porn games.
Was horny, somehow found nutaku, played nutaku games, said "this shit is p2w bullshit" and found itch.io nsfw. Then I just kept on going deeper and deeper lol. I currently am in the LewdCorner era, whatever comes next? idk, haven't discovered it yet
Leisure Suit Larry was the first contact (Baby brother in college showed it to me in the late '80's).
Fast forward 15 years. I was looking for something, I don't even remember what, and stumbled on a website made by "Detonator Orgun". It was a repository of AIF games. Picked one by a guy named Chris Cole, figured out how to run "Adrift", and have been addicted to porn games ever since.
Part memes with friends where we voiced all the characters on discord (was suprised that It was mostly women that were up for it) this is after we streamed Doki Doki. And part a friend gifting them to me on stream. After I saw the appeal
First it was porn comics and then 3D videos. While looking for those on porn sites I discovered some gameplay videos of visual novels and stuff. And then I found some site where you can actually download those games. And then another site and so on.