Savory Subplots in Lighter Fare

I recently wrote a story with a main character in an enmeshed, codependent relationship with his best friend. Months before the story opens, he begins the long journey to end the unhealthy nature of their relationship while attempting to salvage the friendship. When a new love interest shows up and it gets serious, his friend clings for dear life. He knows he needs to make even more of a change if his new relationship stands a chance.

Sounds like a meaty, angsty book, right? In fact, my story...