Suggestions for turning off the mama radar?

[Mamusia]

My breastfeeding, co-sleeping 21 m. old is a champion sleeper--as long as there is direct physical contact with me, preferably skin-to-skin. Little feet on my leg, a little hand tucked into my cleavage, little head in my armpit... but break that contact, no matter how slowly, carefully or stealthily, and the little turnip is awake minutes later. No substitutions seem to work--the papa, the cat, the favorite stuffed animal, a delicious-smelling nursing top, etc.

I just can't spend 10-12 hours in bed every day any more; been doing that for almost 2 years now, and it's starting to affect my health.

We conquered the all-night nipple fest using a variation on the Pantley technique, but this problem is proving intractable.

Any ideas at all? I'd be greatly thankful.

[LCBMAX]

The amazing thing that has worked for similar seemingly intractable issues for me and a few friends is... to ask the child. Even if your little turnip can't verbalize something you might get his brain working on the issue this way:
"Sweetie, mama needs to sleep better so I can be a more fun mama the next day. To sleep better, I need to sleep alone from bedtime til morning (or x to z). What would you like to snuggle with instead of mama?" The cognitive skills of your turnip might be equal to understanding that your separation in the bed is not leaving him but preparing for a trip to the zoo together. He might even be able to offer the substitution that he really wants.
Good luck. I myself was never even able to pee at night without causing a major wake up til I left the family bed. Nightweaning and switching to daddycuddles went much more smoothly when my son understood why.