Yeah, this is one of my big ticket turn-ons. I can't speak for other people on this one, I ended up with this one through a fairly convoluted process.
Let's start with where it comes from. You probably aren't phenomenally interested in hearing about my adolesence, so I'll keep it brief. There's no one work I can point to that did this to me, rather it's a product of the way I played a lot of porn flash games back in the day. It's this situation where the way I played most of those games when I was trying to get off, in key cases, left the character stripped and splattered. And then as I played more and more games like this it became something I looked out for specifically. It helps that it isn't an easy itch to scratch in full. Most porn games get close in places. Almost none get to where I want. Like another one of my big turn-ons, part of it is simply not being able to see as much of it as I'd like, and another part is it feels like the "mountaintop", things like facials are a lower down the same "mountain".
There's a couple of key components to it to. It's not as simple as "naked and splattered with cum in public" though that's close. I guess I'd narrow it down to two key variants, shameful and shameless. Shameless is what you're asking about so we'll start there. And simply put it's a measure of a game world's freedom and interactivity. It was a fairly simple litmus test for how much I was going to enjoy something back in the day. It's almost like a series of questions. 1) Can you take your clothes off? 2) How much sex is available? 3) Are there any lingering effects or consequences? 4) Does the world react to any of this? And somewhere along the way the middle meeting point of all these questions, the centre of the Venn-diagram, became the biggest turn on of them all. It's a game only thing. Sort of. I can't find irl videos that scratch this particular itch, and for good reason. Stories don't capture the interactive nature of the fantasy, and pictures are similarly few and far between.
This is the magic point you hit in UMCC. Now the interesting part of all this is once I've established it can be done, it quickly loses its shine. Knowing it's there doesn't, it actually gives me a pleasant, long-lasting buzz about a game to know that I can go back to that point. In the long run I don't think I bothered more than a couple of times in UMCC. Because a part of me remembers that it was never about the cum-splattered nudity in the first place, it was just a way of testing where the game's limits were.
The shameful variant is of the two is a more concrete fantasy. It has components too, but these are definite and are more simple than yes/no. The components are 1. Naked 2. Cum everywhere 3. Sexual humiliation 4 Submission 5. Widespread exposure of the above. Again, it's the "mountain top". The key implication of all the cum in this one though, is usually sex with a lot of men mostly at once. This might be rape, it might not be, doesn't matter too much, though a better story is always better for my enjoyment. The widespread exposure has a bunch of possible mediums, the obvious one being a walk of shame. Pictures/video getting out also work to an extent.
Finally a word on sluttiness. Which is to say it's actually a separate issue. In the shameful case there is some amount of "sluttiness" involved in engaging in group sex, but it can also be forced, in which case I don't really consider it slutty at all. It doesn't have much bearing on the shameful variant. The shameless variant, I've said is a game thing, I guess there is one corollary, like you talked about a lot of games have corruption/purity/sluttiness/lewdness whatever stats that serve to gate content, in some cases, in this case, yes there is a sluttiness component, but only because it's mechanically forced. In cases where it isn't, it's implied through action I guess, but the characters don't have any real character in a lot of these games, just actions they can do.
I don't know how much sense this will make to you, but I hope it provides a little of the insight you're looking for.