Dude, Kara/Sam/Lee is totally my OT3 for BSG. They ALL having amazing chemistry together. (I've got a Sam/Lee slashy crack-vid bunny in my head now, which looks like it might be just too much fun to put off making...)

lucyparavel did a K/S/L marriage fic (http://lucyparavel.livejournal.com/21527.html#cutid1) a little while ago--it was a much more dark and somewhat creepy version of how a threeway marriage might come about for them, but it was damn good.