look up any word, like blumpkin:
 
1.
An expression of delight, accompanied by dancing around. Basically saying that the person in question is great, skilled, lucky, etc.

Ususally said in a kind of sing-song way.
"Ooooh yeah! I just won that race! It's my birthday! It's my birthday!"
by Athene Airheart March 20, 2004
 
2.
A social phrase to tell someone to give you a present. because, it's your birthday.
Arny: its my birthday
Michael: So..
Arny: Ahem
Michael: OH YEAH, HERE BRO. -hands wads of cash from wallet-
by CRUNKBEAST December 19, 2009
 
3.
Used by either sex to trick the other party, (usually in a bar)into purchasing you a drink, or perhaps used to elicit some kind of sexual favor later on in the evening.
"How's it going? It's my Birthday tonight!! Oh you wanna buy me a shot?!"
by SOB December 09, 2004