Alrighty then, I'm glad I got my confusion out of the way.
Sorry to sound like some sort of wacko person, but I would absolutely insist on this being a boundary now that you've given more juicy information.
EWWWWW, YUCK, BLAH. (Barfy emoticon, where are you?)
I hear you loud and clear. I'll be anxiously awaiting to hear how you and S deal with this issue. Something tells me you're going to have a wild story to tell!
If he really perceives her this way, Jennifer (and I am going to hope like hell that this is not his perception) then you have nothing to lose by asking him if he's in or out...
But by all means, I think doing something along those lines is best done with a qualified C leading the way. I tend to be a little like Denver's answer to Yosemite Sam when holding a boundary that is very, very important to me. (And I don't think you are being unreasonable for wanting her to be an exit into the mutual lives of S and Jennifer for here on out. Three IS a crowd.)
Hugs and more apologies!
Betsey
"There are only 2 ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle."
Betsey 
