Don't do the spicy food. Once your far into the relationship farting during sex is no big deal. But early on, you DON'T want that to happen.

I remember this one time with my last gf, she was giving me head and I let out a blast after we had gone out for italian beef and tamales, and my god, it was foul. I let it loose practically right in her face, and was in tears I was laughing so hard. But she got her revenge. There were numerous times that she ripped ass while I was going down on her. And it was nothing more than cause for us to share a good laugh.