I had a FWB like her. She used to pogo on my dick and howl like banshee the whole time. I used to nut inside within seconds. Eventually we had a custom where she would blow me before sex, and I would cum in her mouth. Then, having already cum once, I could last a good long time.
I probably woukd have came sooner. I can fuck my wife for 30 minutes straight but as soon as i have sex with a fwb or stranger i only last a few minutes. Its the feel of a new pussy that gets me every time.