Hi friend.
I am in this fetish since I was 5, I think, years old.
In the following years I was very confused about the targets.
I'm sure I'm not gay...but sometimes I was turned on by male's farts because, I think, that farts were the only contact to the fetish I have had.
I remember a time I was turned on by series of farts coming from my grandmother too. EWWW!!!! If I think about it now I think I vomit!!!
But later I experimented a lot of female fart smell by classmates that were not shy with farting. One time one of them, that likes me very much, maked me smell her nude asshole...it smelled like fonzies. I think the fonzie-like ass smell is the best.
Any way...don't worry if sometimes you are excited by unusual people. The only concern is to resist to the worst temptations in order to not become a maniac.
It's like all other things...the correct dose is arrousal, but if you cannot limit yourself it's a poison!

Sorry for my dusty english(I'm italian)...but I hope my words have helped a little