I was invited to this birthday party by one of my (female) classmates. It was her roommate's birthday. So I arrive and introduce myself to the birthday girl.

Beautiful brunette bday girl: i'm 23 today lol etc

Me: ah, a prime number!

Girl: uhhh ok sure

Me (in an awkwardly loud voice): ALSO THE TILT OF THE EARTH IN DEGREES

Girl: ok nice to meet you...


I didn't talk to her for the rest of the night. How to talk to girls?