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It was published in the print zine As I Do Thee #18.
"T'Pau has blackmailed Spock into contributing to Vulcan's genetic banks before allowing the ENTERPRISE to leave Vulcan orbit... but the task is easier promised than achieved."
Reactions and Reviews
After Spock’s aborted bonding, T’Pau demands he make a contribution to the genetic gene pool. She orders him to masturbate, collect the semen and get it to Healer Selon asap. Spock, of course, is mortified, embarrassed, etc. … and botches the job. But there comes eager, good old reliable Kirk who’s an acknowledged expert and with the helping hand(s) of a friend, Spock passes with flying colors, so much so that Kirk is speechless by the amount of semen he produces. If the story had ended there, it would’ve been perfect, but the author added an epilogue set after V’ger. We learn that save for that one sexual encounter nothing happened. Kirk is determined to change that if Spock is willing. Spock is very willing and the rest is history. I don’t know if the author deliberately planned it that way or if it was intended as a bonus but I prefer it without the added epilogue which really doesn’t add to the main story, but can stand out as a separate story. It’s fun to read, with an easy flowing humor and on the mark characterisations. 
Riveting from the start! Takes right off from the sickbay reunion scene in Amok Time and never loses a beat! The conversation is right on, the looks, the characterization, bring new life to this favorite of episodes. TPau has surfaced with a new demand—that Spock contribute his fair share to the gene bank. His explanation to Kirkof this duty is so truly Spockian it makes everything so very realistic. Not too soppy, not too silly, just very, very Trek.
Even through Kirk's most logical and friendship- inspired assistance, every word rings undeniably true, bringing a strength to this account that it might not otherwise have had.
Surprisingly, the storyline broke off abruptly following 'the contribution" to be resumed after V'Ger. This is where the author chose to reunite them, again retaining the quality of realism she managed with every step.A read-it-again-right-now K/S contribution. 
- from The K/S Press #22
- from The K/S Press #50