guy 1:  dude, did you know jay leno is a birthday buddy with jessica alba? guy 2:  yea, i saw it on the tonight show last night
someone who has the same birthday as you
"guy 1:  dude, did you know jay leno is a birthday buddy with jessica alba? guy 2:  yea, i saw it on the tonight show last night" What is the definition of "birthday buddy"?