Top definition
Obligation-free sex which happens on or around someone's birthday. Usually initiated by the birthday boy/girl's partner, and involving a mix of acts which more favour the birthday boy/girl's preferences.

The usual rules of reciprocation and mutual pleasure are temporarily suspended, and the birthday girl/boy is considered free to cum whenever and wherever the fuck they please.
Nah, can't come out tonight... I'm hoping for birthday sex.
by evilbrent September 19, 2006
Get a birthday sex mug for your buddy Larisa.
Sep 11 Word of the Day
when you're hungover as shit after a spending a night drunk as a skunk
I'm hungover as a duck let's go get some grub
by pokeythepony June 25, 2021
Get a hungover as a duck mug for your Facebook friend Sarah.
2
the best kind of sex and the best present ever. when your girlfriend/ boyfriend/ wife/ husband/ fiance/ your one night stand has sexual intercourse with you on your birthday
baby for my birthday this year I'd love to have birthday sex with you.

what are you doing on your birthday? sorry the mrs is coming over to give birthday sex
by smoked fish February 17, 2017
Get the birthday sex neck gaiter and mug.
3
having sex to celebrate your parents having sex
Guy:"do you want to have birthday sex?"
Girl:"you celebrating my parents having sex"
by calmyourtiddies March 03, 2020
Get the birthday sex neck gaiter and mug.
4
When a person receives some fucky on there most special day
Chad : Happy Birthday baby I got you something close your eyes!
Kiersten: Oh Chad I love you what could it be?
Chad : AHHHHHHHH!
Kiersten: Wow it's your monster cock do I get some Birthday Sex?
Chad : Yes! Yes! Yes! Strip it down!
Kiersten: Uh! Uh! Uh! Uh! Uh! Uh! Uh! Uh! Uh! Uh!
Chad : Ah! Ah! Ah! Ah! Ah! Ah! Ah! Ah! Ah! Ah! Ah!

Chad : AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH!
Kiersten : Yummy!
Chad : Happy Birthday To You!
by SlopNChop December 18, 2016
Get the Birthday Sex neck gaiter and mug.
5
its when you get some sucky or some fucky for your birthday, with no relationship needed
he got her poosy for his birthday, and theyre just friends
by jhjsahdsa October 23, 2004
Get a birthday sex mug for your sister Helena.
6
A Miller Lite, Bud Light, or other light beer served in a bottle with one sip replaced with a shot or half shot of vanilla flavored vodka (Svedka, Smirnoff, Stoli, etc.) Put your thumb on the top and gently flip the bottle over to mix. Tastes like cupcakes.
how'd you get so fucked up on just bud light?

i was actually drinking birthday sex.
by brokedownman July 19, 2010
Get a birthday sex mug for your mother-in-law Zora.