Contained within the simple geometry of a love triangle are all the ingredients for an engrossing plot. There are characters (desired and desiring, therefore compelling); conflict (fights and lies and changes of heart); and resolution (someone will win, someone will lose, the triangle will be broken apart). Is it any wonder, then, that we return to these stories again and again?

In his newest novel, I Loved You More (Hawthorne Books, April) Tom Spanbauer manages to give readers a fresh look at this well-worn story. Spanbauer, whose works explore issues of sexual identity, race, and family, is the author of four previous novels and the founder of Dangerous WritingBen, the narrator of I Loved You More, explains the appeal of the love triangle: “With three you go directly back to the father and the mother and the child. Or this: a parent and two children. In either case, you’re back to what’s most fundamental about you: who has the love and who’s going to get it.”

The love triangle, then, is archetypal, and as a literary theme, it’s been with us for a long time. Shakespeare, for example, gave us a love triangle in Twelfth Night, created in part by mistaken identity, as one of the characters, Viola, spent much of the play disguised as a boy named Cesario. Viola loved Orsino, while Orsino pined for Olivia, and Olivia fell for Cesario.

Gender is a main issue in the creation of a true love triangle. While Shakespeare addresses this with a cross-dressing character, other authors simply subvert the geometry of a triangle: Boy #1 and boy #2 both love the same girl. There are two arrows pointing in the same direction, but the triangle has no base. Pride and Prejudice by Jane Austen—in which Mr. Darcy and Mr. Wickham both compete for Elizabeth’s attention—is one example of such a plot, as is F. Scott Fitzgerald’s The Great Gatsby.

Jeffrey Eugenides’s most recent novel, The Marriage Plot (FSG, 2011), is a more contemporary take on the same story. In it two young men—Mitchell and Leonard—are both in love with the romantic and naïve Madeleine. Heartache ensues. While I Loved You More has been compared to The Marriage Plot, Spanbauer has actually been able to do more with his love triangle than Eugenides did.

In an article that appeared in The Wall Street Journal in 2011 listing some of the best love triangles in literature, Irish novelist Anne Enright wrote, “For a love triangle to really sing, all three people must love each other, gender notwithstanding.” Reading between the lines, what this means is that the most compelling love triangles are those that are willing to explore the full range of human sexuality.

Spanbauer does just this, presenting us with the story of Ben, Hank, and Ruth. Ben, who is gay but has had relationships with women, met Hank at Columbia, and while Hank is straight, the two form a loving and complicated relationship. Nearly ten years later, Ben falls in love with his writing student, Ruth, and the two become involved. When Hank comes to town, Ben introduces him to Ruth. Geometry becomes complicated.

 A more apt comparison for Spanbauer’s book, then, might be Michael Cunningham’s Home at the End of the World (FSG, 1990), which also depicts the relationship between two men—one gay and one more or less straight (though open to experimentation)—and a woman caught between them. What makes these “complete” love triangles intriguing is the blurred lines they create between friendship and love. While Shakespeare offered us cross-dressing as a way to push beyond the binary notion of love, Cunningham and now Spanbauer have given us a more complex view of human sexuality, and what it means to really love someone.

For anyone interested in the messy geometry of human relationships, Spanbauer’s book is a must read this spring.