Jesus. At first I was all like "ooh, a butterface...I'd hit it". She does have a nice bod. Her vulgarity, the enthusiasm with which she farts, and imagining the smell in the room; these things combined to fill me with disgust. I would say that I feel sorry for her boyfriend, but he probably likes chilling in the miasma. Definitely evil enough.
The farts are definitely fake. The reverberation she is getting on the seated ones is not realistic. A cushioned chair changes the timbre/mutes it a bit and a few of them are shot almost directly into it.