Selfishness

Question what make someone selfish?
Most people would answer a person who only center in themself. after a long pool party yesterday i wanted to go home, so i called my brother to pick me up in an hour because i had to go to another friend house to get my clothes back. The time was going to be sort of like close to twelve but not pass it. My brother call me back that he was in a party and asked my if i can hold it a little longer so he could stay a little longer in the party. i said yes. i stayed with my friend a little longer. We were very tired and we talk for like an hour and then just felt asleep in the couch him, and i in the floor. it was two am and i called my brother.
"So where are you?"
"Still here."
"Okay" i hung up.
Three, and four am passed and at four fifteen he dare to call me and tell me he is on his way. at four thirty i call him to know where he was; it was taking him too long.
He answer me "I am looking for my keys." i was angry, pissed off. He was still there.
It was almost five am when he came to pick me up.

So here is the topic. Who was selfish?
Me for wanted to leave, and pushing him to leave the party to come and pick me up? because my friend was tired too, and i wanted him to rest also?
Or
My brother who did not care about me and stayed at the party for six more hours?
i was just so pissed off that i wanted to say something but i did not say anything. i was silent and i am still silent. no longer mad at him, but wondering who was selfish.