Can't say I know it, but that seems really good. I would like to read that too.
OMG! I READ THAT TOO BUT FORGOTTEN WHAT IT'S CALLED! BuT I READ IT ON MYREADINGMANGA.INFO
sorry about caps I've been looking for the same manga too
That's also where I read it and I've tried like crazy to find it, but till this day I've never ran into it not even in the recommendations that they offer.
If you're still interested the name is Tatau no Taiyou and my description of the one shot is quite a bit off though I was able to find it in the end.^^
The uke ends up on some deserted island and he ends up running into the seme (I think he's a warrior). I don't remember what happens next, but then they end up doing it. Next day the Uke I believe is rescued and he goes back home, later on some person ask him if he knew the true meaning of a tattoo he has, which he got during his stay on the island. So, anyways the tattoo means that he is married to the seme and that is where it ends.
It would mean a bunch if someone could tell me the name of this yaoi one shot. I only read it one time and me being me didn't jot down the name. I hope this is enough for someone to recognize the one shot.
(Update 8/29/16)
I was able to find out the name of the one shot, the name of the one shot is called 'Tatau no Taiyou'.