I have had a few over the years but only one was memorable . In all of my experiences, there has been little or no interaction, between the girls.
My best experience was a MFFF, with three sisters, the oldest was about 30 , attractive, the middle one was good looking, mid 20s and the youngest was a smoking hot 29yr old. This was in Morocco, quite a number of years ago.
I had arranged to meet the young one, who backed out last minute, citing her sisters had come to visit. I invited all three to a club, they accepted.
Went to a club, came back to my place, more drinking and then the bombshell , the big sister insists that I can't go with the young one, as she was still a virgin and going to be married soon. I already knew about her being a virgin and we had agreed on oral and anal only , but big sis was not having it, she offered me the middle one, this was a two bed apartment, so off I went, after a couple of hours and two shots, the young one comes and gets into bed with us and I managed one shot on her. We managed to sleep for a few hours, in the morning big sis barges in and I'm butt naked trying to calm her down, she ends up in bed with us also, a lot of kissing, fondling and sex, however , zero interaction between the sisters.