This is best policy especially where the woman is hot. I was seeing one woman who was stunning used to pick her up from the train station. But she knew and was fully trained the procedure. Strip down once indoors, would be a full load in her mouth. Then she freshened up for me took a shower and second load would be in the vagina. You will last way longer if you have already busted that first load
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.