As a girl, the masculinity and no-filter aspect of it is what really turns me on about it
I (18F) was trying to think about what exactly it is about guys farting that turns me on... and I've figured it's the masculinity and no-filter part. The masculinity part is kinda simple... we tend to allow men to be "grosser" than women lol and I'm one of those people. I like to be squeaky clean and get grossed out when other girls aren't, but for men it sorta reinforces that masculine side of them.
Kinda the same thing, but the no-filter aspect to me is who guys really are when they're not trying to impress a girl. I always view it as like a guy just hanging out with his "bros" and fooling around. It may just be me but most of my friends are guys and I'm usually the only girl in the room... so they forget I'm there and will all fart and laugh about it. Locker room talk almost lol