This is going to be a bit harsh critique I guess.
I read your profile and you said you want to learn to do portraits well.
So by saying how much I like this, you won't learn I guess.
Let me say first that I like the idea, and that your photo is crisp and sharp.
But there are some distracting things going on here.
As people mentioned, the gray on the womans face looks very unnatural, and the face of the man is too dark.
I am not a portrait master or a studio expert, but the lighting, intentional or unintentional is not my taste. There is a big black shadow on the guy's face, and some major hot spots on the womans face.
If you have those two flashes, with softboxes and umbrella's just go and experiment with light setup, get your girlfriend, kid, brother, sister, mother over for a cup of coffee and start shooting until you really understand what those flashes can and can't do, why they do it and how to use them in different situations under different circumstances.
Practice makes perfect.
This has potential, if you put your mind to it, I know you can do it.
I'll keep my eye on you and see what you come up with.
The over powering white background.(even though it a good choice) Defusses the over all picture here. The light it self is wrong and in the wrong place. The colors on the faces are to dark when the face are so bright looking. To many shadows. And this would have helped with the blacks in the bottom not to fade together.
This is very well done, except, for my tastes, I think it would have made a better portrait to just have her in it since she is posing so well, and it looks like he got caught off guard.
On the right side of this models face there is a grayish tint that is very unappealing. Im not sure this was intentional or unintentional, but it is distracting, and gives the picture no justice. I hope this comment helps. GL.