Ok, being a girl, who was a vegetarian when I started seeing my now-husband...
I had to fart. We were spending WAY too much time together, and I couldn't hold it in anymore. I made an announcement (as I was seductively crawling naked towards him in bed, fellas
) that I HAD to fart. So I did.
And he said "thank fuck, I was tired of holding them in!".
So if you have to blow ass, just try to make it obvious- it's so much worse when one sqeaks out unannounced. Besides, she's probably holding them in too.
Barring that, chill out on the beer and broccoli before a date
And as far as etiquette is concerned, just never near the face, and excuse yourself if necessary. Hell, it's a natural human body function.