I just went through this with my girlfriend, and I was nervous....but then after talking to a few people here, I got the courage and realized she wouldn't see me any different...and it's been great ever since 🙂
I'm not saying this is how she'll react, because of course I don't know her, or your relationship.
as for your other question, yes, i'd be totally okay with a significant other having a fetish that I didn't have...my gf definatly has a few 'kinks' of her own that I tend to, and she in return tends to mine..
good luck!
It can be very nice when it works!!.