This could be a fun idea. (and inspired by another post - which insisted it wasn't about having an affair).
Of course it, has to be far away from the "other". If you're on the west side - are you safe going downtown? The valley?
Had a friend who had a girlfriend, fell in love with this model turned screenwriter. And he asked her out. He did some research for something interesting and obscure. He found it - a Latino transvestite bar in East L.A. He takes the date there and a few drinks into the evening - in walks his girlfriend! And his comment, priceless "Of all the Latino transvestite bars in the world...."
Anyway, I would say if the "other" doesn't like a particular cuisine - then that settles it.
But someplace obscure and interesting. And if not on the outskirts, in an unconventional setting where you'd probably not run into anyone you knew.