I had seen this before in sex videos and the secret both times were vigorous good handjobs and the male getting visually very simulating views.
I once had a similar double orgasm with the first orgasm being from scissors position intercourse but in a somewhat uncomfortable awkward position so my climax felt incomplete and the second within a few minutes from a combination of hand and oral sex where my lover was in an awkward position against the wall off the bed but which I thought was visually very stimulating.
I remember thinking God I am fucking you in your mouth and your hands are stoking it out of me and your tits and face are so beautiful and I am going to come again.
Here is a bonus of someone else who really knows what she is doing.
Busty babe gives a POV handjob brought to you by PornHub