This is the result of a weird triangulation of two fics by two different people. One is A Night At The Opera
by tigerlady, which is an Elizabeth/Teyla/Ronon story, and the other is A Celebration
by thegrrrl. "Night At The Opera" left the situation open-ended, and then after I read "Celebration" I was teasing grrrl about what Teyla and Ronon were up to while John and Rodney were in the bathroom, and the ideas sort of came together.