My first time I literally lasted 20 seconds. Just kept on going until I went limp. It was with a girl I was cheating on my gf with and I had lied to her and told her I wasn't a virgin, so to play off the 2 minutes of unsatisfying sex I was just like "I can't do this to my gf, I gotta go" and snuck to the bathroom to dispose of the used condom. Used alcohol the 2nd time I had sex with her and lasted forever.

tl;dr - Drink alcohol to last longer.