sexversary 

the anniversary of the day you had sex. most easily observed once pregnancy begins; in this sense, also known as conception day.

"happy sexversary, friend with benefits!"

"wow, amy and tom! happy sexversary, and welcome to the third trimester."

sexversary by janice jim July 13, 2009

semiversary 

6 month aniversary.

A shortened version of the word semianniversary.

On the inside of a card:
Happy semiversary

semiversary by KoH March 20, 2007

Sexiversary 

The date on which two people first had sex.

He was invited out for a drink after work, but he knew that since it was their sexiversary and she would be expecting him to be on his game, he declined.

Sexiversary by Kate Charlton June 18, 2008

sexessary

A Necessary Fuck. One that is required either arising out of circumstances beyond the control of the participants or due to an extreme sexual attraction that can only be settled with a good toss in the sack.

Etymology>>> Sex ( the act of penetration) + essary (required or obligatd)

This girl is so hot, its about to get sexessary.

sexessary by Truth is not an ideal, either September 22, 2011

Sexversations 

Communication, dialogue, discussion, or conversation that promotes personal sharing, inquiries and critical thinking around all things sexual. Healthy sexversations are framed around safer sex practices, consent and empowerment.

Frequent sexversations increases your sexual IQ.

Sexversations help break through societal myths and taboos.

Sexversations by Sexpert at In Our Own Voices June 25, 2013

Sexiversary 

The date on which two people first had sex.

He was invited out for a drink after work, but he knew that since it was their sexiversary and she would be expecting him to be on his game, he declined.

Sexiversary by Kate Charlton June 19, 2008

sadversary 

Someone who sees themselves as your rival or enemy, but is just too sad for you to bother with.

Art liked to think of himself as my nemesis, but he was just a sadversary.

sadversary by Gazira June 24, 2011