See subject. I expect there will be a variety of answers.
Bedsheets? Clothing? How do you know it’s semen if it dried? What practical use will you put the answer to? If it is clothing, I’d put it in the washing machine. Bedsheets, I’m sure I’d do the same. Are you trying to conceal the semen from discovery, or does its mere existence bother you? Is the stainage happening so frequently that the washing machine isn’t practical? Is the stainage infecting clothing, so you wish to conceal it before sending the cotton items to the laundry? More details, please!
Maybe the cotton in question is a blue dress?
I have three (3) freshly dried semen stains–or had at 10:20 AM–on the left side lower portion of the front of a black t-shirt. One, looking slightly like Japan tilted East-West, is approximately two inches long. The second, larger and in the shape of Hungary, pre-Trianon Agreement, is two (2) inches North with the same center line, running S-NW. The third, a small non-descript island, lies an inch to the East.
I wished, at the time, to conceal the stains so as to get a second day to wear the shirt without alerting observers of same of a recent–because not yet yellow, but perhaps that is immaterial, as it were, with a black shirt–sexual act, said stains being more reprehensible in the public eye than those accruing from work in a dusty attic, gardening, or futzing with your car, for example.
ETA: I know it’s semen, and mine, if that information is helpful, because I was there when it happened. And I have an eyewitness to uphold my alibi.
“Need answer fast”
Also: why does dry semen turn yellow?
And no, these are not questions I think of in the afterglow. Of sex, that is, not reading SD.
…what?
Protein stains like semen and blood typically require a detergent - which is not the same thing as soap - to remove. A detergent with enzymes that specifically attack proteins would be better.
To the Op: sorry, but I don’t believe you.
Geez…how stupid do you think we Dopers are?—that we’ll just fall for any lie you tell us, huh?
Sorry,---- but your facts just don’t make sense, and don’t hold up to the standards we expect here.
You try to claim that the second stain , the larger one, is shaped like Hungary.
But the area of Hungary, pre-Trianon agreement , is 14% smaller than the area of japan.
Please–if you must spill stories --do not disseminate ignorance.*
*(yes, thank you. I thought it was a pretty good pun, too. I’ll be here all night… In my bunk 
)
Fair enough, however if you are going to be in your bunk, you might want to subscribe to this thread so that you can get tips on how to get rid of any…uh… messes that might develop while in your bunk.
Umm…it’s kind of yucky to wear a semeny shirt. Why not just put on a clean one?
Yeah - or if circumstances absolutely impose the necessity of rewearing the garment, contrive to spill some ketchup or gravy on it to conceal the embarrassing stains.
Has anyone noticed you’re showing some spunk?
Post 9 years old, ketchup and gravy stains are pretty embarassing too. Funny-embarassing though, not ew-embarassing, so yeah, do that.
Exactly - “I can’t believe I spilt gravy all down my damn shirt! Silly old me!” = funny.
“I can’t believe I jizzed on this shirt - right here - see?” = awkward silence…
Is that “what” as in “that doesn’t jibe with my experience,” or “what” as in “who you callin’ yellow?”
A drop of dish washing liquid? What is a detergent with enzymes that specifically attract proteins?
And the above as opposed to liquid hand soap, you say? What is the difference?
I will, if I see fit, respond in due course to the additional queries put to me, aspersions included.
For now, yes, semen stains on white cotton does turn yellow, as can easily and not-unpleasurably found by experiment. I don’t know why the color change occurs.
As in, “holy shit, that’s a thing?”
Very much so. As a teenager, I became quite aware of how semen turns in paper towels over time. Yes, I was disgusting. I was a male teenager.
A s a teenager, when some semen was deposited on any material be it clothes, towels or bedsheets or whatever, we used to say: “Zap, instant cardboard.” Hadn’t thought of that in years.