Outlaws of Love--Billionaire Menage Romance

Everything was perfect for Melissa and Nathan. Nathan was a billionaire. He had so much money that they did not have to worry about anything. Melissa could buy anything, travel anywhere, and do whatever she liked. One day, Nathan proposed, and Melissa could not have been happier. But soon into the engagement, he suddenly packed his bags and abandoned Melissa without an explanation. Returning five months later, he pleads for her forgiveness. Melissa is angry, but comes up with an idea for winning him back to go on with their marriage. But little does she know that he has a very dirty secret. It turns out he's a bisexual. Not only that, the man he cheated on her with was another billionaire, and also her ex-best friend. Once she finds out, how would she be able to cope with it? Will she take Nathan back as her fiancé, or will she forfeit her plan? 
A Standalone Short Story with No Cliffhanger!