look up any word, like the eiffel tower:
 
7.
The Mandatory Sex Party is a socially radical minor political party founded in October 2009, in the back woods of Montana. The Party's federal chairpersun is Allie Brosh. To date they have no elected members but momentum behind the MSParty is growing.

The MSParty believes in prosperity through population, coining the slogan, "Breeders are Leaders". In a political climate where many governments are contemplating the challenge of stemming population growth, the MSP takes the stance that population growth will provide the global community with the next generation of scientists, doctors, philosophers and theologians necessary to save the planet. They believe that population suppression risks the prevention of our future leaders being born.

The MSP launched a modest election campaign for November 8, 2011 cantered in Montana, with candidates also campaigning across Wyoming, North and South Dakota. A primary campaign tool being utilised by the MSP in this election race are 'mandatory sex parties'. The MSP, with its many policies supporting family growth, are encouraging supporters to throw pre election mandatory sex parties in the anticipation of having many blossoming families behind their podiums come November 8. Founding member Allie Brosh has been quoted on-line saying that the Party believes in growing their support across generations.
MSP supporter -I'm throwing a pre-election mandatory sex party this weekend, are you going to be coming?

MSP supporter's associate -I don't really know, I guess I've been thinking of looking into it, their policies and motivations seem sound. Who else is coming?

MSP supporter -Well we're quite excited, Allie Brosh is going to be there to give some motivational foreplay.

MSP supporter's associate -So the sex is really mandatory then?

MSP supporter -Yeah, hence the mandatory. Did I mention Allie Brosh is going to be there..?
by ShastaBare August 04, 2011
 
1.
A mandatory sex party is like a normal sex party, except if you don't attend you get arrested. People are told they will be attending a costume party, but what really happens is a wild, out-of-control orgy involving beer, fire, and moving logs onto the road.
Allie: So, how was your costume party last night?
Roger: It turned out to be a mandatory sex party.
Duncan: Those actually exist???
by Alliestalker October 14, 2009
 
2.
"A party where once you walk in the door, you are obligated to have sex. I would think that these parties often disguise themselves as costume parties or birthday parties or baby showers but THEN as soon as they entice people in the door, they are all "guess what this actually is? It's a mandatory sex party, bitch!"
I went to Allie's blog expecting some kind of awesome party with lots of pie, but as soon as I got there everyone was like "guess what this actually is? It's a mandatory sex party, bitch!" and then the raping of my eyeballs with awesomeness commenced.
by Havoc8709 March 31, 2010
 
3.
Sex parties in which attendance is mandatory. Most frequently seen as part of a sex course or among couples who practice both swinging and S&M.
"Sorry Kelly, I can't make any prayer meetings this week. I have some mandatory sex parties to attend."
by adelaidepoet October 14, 2009
 
4.
Any party that occurs after some sort of population-reducing apocalypse including, but not limited to, 2nd Ice Age, Zombie apocalypse, Nuclear war, or Donald Trump being elected President of the USA.
In this post-apocalyptic world any gathering of people, such as at a party, will be required to engage in coitus so as to re-populate the world, the only people being exempted are those who are already pregnant.
Allie: The apocalypse has left me with so little to wear to the party tonight!
Melissa: That's alright, it's going to be a mandatory sex party anyway!
by Monquiis November 25, 2010
 
5.
When someone invites you to a birthday/frat/whatever-other- kind-of-party-you-can-think-of party and it turns out to be a sex party. If you refuse to participate, you will arrested. Hence the "mandatory".
Markus: Yo dude, how was that party you went to yesterday?

Ken: Dude, it turned out to be a mandatory sex party!

Markus: Oooohh! Dude you got BURNED! HAH! So did anyone get arrested?

Duncan: WTH!?!?!?! Those are real?!?!

Allie: Told ya so!
by Yourwordinformer January 24, 2011
 
6.
A party that is disguised as a typical type of party, but really requires you to have sex throughout the night; Obligated sex with multiple people; Raping is involved. The Amazing Allie from Hyperboleandahalf.com coined this phrase.
Guy 1: Jill invited me to her Halloween Party. You goin?
Guy 2: Nah, the only type of party she has are "mandatory sex parties"
by Mandatory sex party goer January 26, 2011