Part-Time Lover

It was only supposed to be a marriage of convenience...
Let me just say, this whole part-time lover thing was her idea. I'd have gone all-in from the start, but hey, when a gorgeous, brilliant woman invites you into her bed, and only her bed...well, I said yes.
But then, one hysterical phone call from my brother later, begging me to find myself a wife so grandfather's business stays in the family, and I need a promotion with Elise. Turns out a full-time husband suits her needs too, and a temporary marriage of convenience ought to do the trick, until we can simply untie the knot...
As long as no one finds out...
As long as no one gets hurt...
As long as no one falls in love...
But our ending was one I never saw coming.