Well, technically, deviation just means going by a different route -- you know, to deviate. It means, without the moral baggage, that you are aroused by something different from the mainstream.
It is true though that people pile on negative baggage about people who are different, but they are going to do that whether you use the word "deviant" or not.
There's also the whole issue of sexual fetishism. Technically, it's a sexual fetish if reaching climax involves an object (or activity) not related to "normal" intercourse. So if, say, feet arouse you, but you can have normal sexual relations with a partner without any touching/tickling the foot during the sex act, it's not a fetish (again, technically). The popular usage overwhelms the scientific one, though, so anyone who is "into" something that doesn't involve mainstream interests is a "fetishist." Again, the baggage gets piled on. It's "normal" to be aroused by breasts (a body part not part of intercourse) but a "fetish" to be aroused by feet.
Such is the world we live in ....
