Two guys and a girl

Buck and Brett were best friends. Jasmine was Buck's girlfriend, although he sometimes took other girls out on dates. There was always the unspoken assumption that Buck would marry Jasmine. 

When Buck was drafted, he knew that would be a dilemma for Buck. Both guys were in love with Jasmine. Brett loved her for all the same reasons Buck did. Although Brett would never intentionally betray his best friend by dating her behind his back while Buck was off on the war front, there'd be a powerful, even overpowering temptation. This was his one shot at Jasmine. A once in a lifetime opportunity to win her heart. 

As a matter of fact, that's exactly what Brett was thinking. He was torn between love for Jasmine and loyalty to Buck. He'd feel horribly guilty if he double-crossed his best friend. He'd be afraid to tell him for fear of ruining their friendship. Yet not confessing would be a cloud over the friendship. 

A week before he deployed, Buck had a talk with Brett. He gave Brett permission to date Jasmine if he wanted to. It's not that he liked the idea of Brett dating her, but he didn't want her to feel that she was stuck with him when she'd rather be with Brett. And even though he had a soft spot for Jasmine, all the girls he knew were kind of interchangeable. He could always find another girl, but his best friend was irreplaceable. Some things were unrepeatable. And he didn't want Brett to resent him for refusing him the chance. 

Brett was stunned. When Buck shipped out, Brett took advantage of the offer. He dated Jasmine all summer long. They had lots of fun. But in the end she didn't marry either one. She ran off to college and married another boy.

They were both disappointed. But Brett was grateful that he gave it a shot. At least he didn't have any nagging regrets about what might have been. And the friendship endured.