To have multiple orgasms, keep breathing as you feel yourself reaching your peak. Do you tend to hold your breath? Most of us do. To have a second orgasm, breathe through the first; your body can stay aroused, keeping blood in the genitals rather than rushing it up to your oxygen-deprived brain.
—The Best You’ll Ever Have: What Every Woman Should Know About Getting and Giving Knock-Your-Socks-Off Sex by Shannon Mullen and Valerie Frankel