-Tribadism, both grinding and with a double headed dildo. In this position both women would be on their backs either braced on their hands or elbows (which could be a way of giving options in the position). In this position they could also have the options of rubbing their own breasts and clit or their partners.
-If the double headed dildo would be implemented both women could be on all fours with the toy between them and they push back into it. With both being able to play with their breasts and clits.
-The the double header has the third person option of the woman on the pivot point.
-Mutual fingering could be several different positions with one sitting side by side with one using their left and the other using their right on their partner. This would also allow a version with the women laying on their backs with their hands in similar positions,as well as a standing position where the women are face to face and able to use either hand on each other. In all three positions the women could also have options of playing with their breasts, and in the standing they could also play with their partners.
-Kneeling oral could have one girl standing with the other kneeling between her legs while a second version could have the receiver sitting while the giver again kneels. A laying down version of this would also be wonderful. The bent of the table pose could also have a woman kneeling between her legs.
-There could also be a purely giving fingering where a giver would simply focus on her partner who could be standing, sitting, bent of a table or laying down. Positions that could ALL also have dildo using versions.
-If you implement other toys like pocket rockets or vibrating bullets that would open a whole other range of ideas, but I'll leave that as a first step.
And yes these also could have FS or even FM variations... but they've gotten theirs as of late so I'm not worried about them
More as I think of them.