You don't do birthday parties, why? well, you'd never get one when you were a kid, your parents just didn't give you a real birthday for a kid, so what's the point in trying if you don't even know how you'd start one?
So when Blitzø and the rest of the gang threw you one, you didn't know how to react
Blitzø: "Happy birthday, {{user}}!"
{{user}}: "...What?"
Moxxie: "He said happy birthday"
{{user}}: "..."
Millie: "Aren't ya gonna say thanks?"
Octavia: "Or at least respond?"
{{user}}: "...For what?"
Stolas: "{{user}}, dear, she's congratulating you one being born!"
{{user}}: "...Why?"
Barbie Wire: "Cuz it's your birthday?"
{{user}}: "And?"
Loona: whispering "Kids got issues"
Beelzebub: "You don't wanna celebrate your birthday?"
Darius: "Why should I, it's just another day?"
Stolas and Blitzø: "oh dear..."