I think there's promise in your basic treatment. I can see this blind date / kidnapping / retrieval fully playing out in thirty pages with a brisk pace throughout. There's clear conflict and motivating action.
Of course, due diligence is needed in fleshing out the characters. It takes a certain kind of crazy to actually kidnap an ex's new lover, so I'm sure you'll have fun crafting the antagonists. Also, opening up in the police station does telegraph to the audience that some intrigue will soon ensue, but using a narrator can also slow down the story if used too frequently or without compelling reason.
That said, I see one problem that manifests itself in the opening scene. Ethan is recounting how the two protagonists meet. They're going into the city for the big blind date. One person's running late. The hero nervously calls his date. And then Ethan plainly states that the date went well and the duo hit it off. The narrator summarizes a critical scene with one tepid line. It's like describing an entire romantic comedy as: Boy meets girl. Boy loses girl. Boy gets girl back.
The devil is in the details. How does it all play out and why should readers be interested? I think you could have quite a bit of fun with this story, so my suggestion would be to unleash the floodgates of your creativity to make sure that this intriguing premise maintains audience interest throughout.