Star Trek Threesomes

Kirk/Spock, Kirk/Spock/McCoy

Running With Scissors Part 1, Part 2 by mrasaki
Warnings: A tablespoon of snark, a teaspoon of schmoop, two cups of porn, mix well. Add crack to taste. Some eyebrow-arguing may be involved.
My Warnings:  Bottom!McCoy, blow jobs (wow, are there ever blow jobs), sick!McCoy (a bit), liberal use of references from other fandoms, amusing, established relationship (Kirk/Spock), threesome

Reaper!McCoy/Spock, Reaper!McCoy/Spock/Kirk

Evidence Required by whiteraven1606
Summary:  Written for the ST XI Kink Meme for a prompt that wanted Reaper!Bones/Spock.  Updated to fill more prompts for Reaper!Bones (now develops into Reaper!Bones/Spock/Kirk in chapter three).
Warnings: Reaper!Leonard McCoy, Spock, James T. Kirk, Christine Chapel, Nyota Uhura, Slash, Biting, Marking, Rough Sex, Fingerfucking, Possessive Behavior, Double Penetration
My Warnings/Opinion: Bottom!Spock, Bottom!Kirk, threesome

It is not necessary to know what it means by Reaper!Bones.  The story pretty well explains itself in that regards.

Chekov/Sulu, Kirk/McCoy/Chekov

Writ Large – The one with the Brindmolian sex-venom by rivers_bend
Summary: Your basic sex-pollen fuck-or-die scenario in which Kirk and Bones are good enough to lend a helping hand or two.
Warnings: “sex-pollen”, double penetration, toys, bottom!Chekov
My Warnings/Opinion: Wow. Oh and a blow job. Finger fucking too.