Thanks Mistress Lana, inspiring. One fantasy that doesn't seem to be represented here involves two women in a stack (like above or facing each other) but with vagibal sex. I read a story which discussed a game "onesies, twosies" where you stroke once in each then 2 in each and keep going until orgasm.
Difficult to arrange safely in a real life scenario except perhaps between honest friends.
The (fictitious) scenario had a group of 8 girls lined up and one guy blackmailed into satisfying them all orally then playing the game.