Okay, I'll bite. I did it this morning. My wife was upstairs sleeping, and I was scrolling through reddit before work (as one does), and something reminded me of the cup fucking post, and the next thing I knew I was grabbing a Starbucks™ mug, putting a latex glove between two sponges, sticking them in said mug, then pulling the glove over the lip.
When I glanced down I was struck by 2 things: 1) I just had just made a "vagina" out of sponges and a cup, and b) I was just about fuck a cup.
Armed with the latest material from my favorite nsfw subreddit, I set to start fucking this...thing.
.....
Where do I begin. I didn't have lube (didn't think I'd need it), so as I was thrusting away, after my 4th or 5th "half, half, whole", my cock started to burn a bit. Undeterred, I kept going, and maybe 30 seconds later the burning got worse.
I pulled out to find the area around my cock head (whatever it's called) was red and raw. To make matters worse, the latex glove I used was powdered, so whatever that powder is made out of (chili peppers, apparently) made the burning that much worse.
Okay, no lube, raw cock, but I'm determined to see this thing through, so what do I do? I added some water to the vagina. Just a little bit - you don't want to have a soaking wet fake cup vagina. Did it make a difference? Nope. It made things uncomfortably louder, and the powder mixed with the water to make a small paste, which of course stuck to my raw cock like...well, latex powder and water to a raw cock.
I'm so ashamed to say this part, but we're friends now, so here goes. All this "half, half, whole" thrusting and latex powder paste burning didn't stop me from finishing, and since I was in the kitchen, fucking away at this fake vagina, I pulled out (as one does), aaaaaand....I can barely type this out....I came onto the opening of this fake vagina.
I know what you're thinking, and in my defence, I didn't want to have to clean up!
Now I've jerked off to some degrading porn in my life, and after all is said and done, I've looked at the open tabs and thought in disgust "what has become of my life??" When I jerked off into the opening of this fake vagina cup, and I looked down at my raw, red, chaffed cock, covered in a slight latex powder paste, I can't describe to you the feeling of disgust I had.
Here's the messed up part: I would do it again! I would probably use lube, or, you know, a condom in there, but I've stuck my dick in far worse. Peeing has hurt like a bitch today though. I imagine this is what it's like having an STI.
TL;DR: Fucked a cup. Burned my cock raw. Would do it again.