Second, it's not oral sex that increases the odds, it's papillomavirus, which can be transmitted through oral sex (but also through other means of sex, including kissing).

You could have oral sex with someone that doesn't have the papillomavirus as often as you want, and you wouldn't get cancer from. In fact even sticking to a single oral partner (e.g. your spouse) reduces the (already small) odds heavily, even if you're not sure whether they have HPV or not.