Take a really long piece of sturdy plastic wrap (long enough to fit around your body about eight times). Then fold it in half, twist it into a long rope that fits snuggly around both of your bodies twice, and secure it with a knot at your waist so you're locked together. (You can also use a Pilates stretch band or a knitted scarf that has a bit of give.) Whether you then get into girl-on-top, missionary, or straddle him face-to-face, you won't be able to move more than a few inches from each other.
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