Story behind the fetish

Have you ever wondered what was the story that made someone turned on by a certain action. Well the psychology class I took tells us that it's a learned response. You pair a certain stimulus with a certain reaction and eventually you can get that reaction from the stimulus. Like you could get certain smells to make a person aroused if enough reinforcement was put in. Anyway I ask that question because I was on xlive looking for vids and I saw one of this guy. I've seen a few of them he posted on the site. Lately when I put my cursor over the image to preview it he looked like he was smeared with mud. Now I thought ok maybe that was some bad tanner. Well today sadly didn't confirm that. He had a vid on there called poppin and poopin. Yeah that was a turn off. Never clicked that video. I know the human brain can do so many things, but I just don't ever see what could happen to make a person aroused by poop. Obviously enough people are aroused by it to cause it to have the name of scat and to have videos put out with it. I mean what in the world could make you get over the smell to be aroused by it. Like I said I know there is a story involved and I kinda (sadly) want to know what it is. Just like I wonder what possesses people to have sex with animals. I mean at least fisting I can get how someone finds that arousing. I don't find it arousing, but I get it. If someone wants to explain it to me I'd gladly appreciate it.
Got to admit this guy is clearly well endowed. There is no stiffness in that pouch, but it's clearly very full. That angle can be very flattering or very embarrassing. I mean this guy isn't the biggest guy ever, but got to admit with that package I can't imagine anyone leaves bed unsatisfied.
You have to be so secure in your masculinity to take a picture like this. I mean clearly this guy's girlfriend is taking the picture. You can see her in the mirror. So I kinda wonder why do I have this picture. Did someone break up with someone. Did someone piss someone off? Then on top of that his pecs actually fill out that top pretty well. Means either his pecs are that big or his girlfriend's tits are that small. Least he has the muscle to beat up anyone that dares make fun of him for this picture.
Seems like every winner has this happen to them. They get so wrapped up winning and holding the trophy and thanking the crowd that sometimes they peak out a bit. Sadly I can't tell how his dick is positioned. Looks like it's sticking forward and if that's true then wow not too impressive flaccid. There is a reason why they always say check yourself.