What on Earth is it with teen guys & pigtails?

Ok, nearly all of my friends are guys and there's only a couple with girfriends & since I'm the only girl in the group, they tend to get a bit touchy. They all have different fantasies with me, other girls, or even teachers. But one they have in common is that they all always ask me to put my hair in pig tails & when I do, they go all gushy. They love pulling them or yanking them or pretend I'm a horse. I have long blonde hair so the Rapunzel thing comes across also. These are guys ranging from 13-15. I just want to know what it is with guys and pig tails.