Darnathi because by default they're a genderless race, don't have much in the way of what we would consider "deviance". Although some individuals have a really interesting obsession with Tails. Silver is one such person. It could be argued it's also because he no-longer has his tail that he now obsesses over his girlfriend's anyway.

Not to say he doesn't love Every part of Artemis's anatomy, but by far her tail is his all time favorite feature. I think she finds it amusing. He finds it a little embarrasing...when he's caught.