Now that I think about it more... this is a good "life" story. It's not a romance, but it's about life.
Life, especially in young adulthood, is a lot of trying things, it not working out as you'd hoped, and figuring out how to keep going despite that. This is a story of that. It's not the end of everything if you try a thing and it doesn't work out. You have your feelings, you regroup, and try something else.
That's normal. That shouldn't be seen as a failure or horrible. That their relationship survived, that they landed back no worse for the wear, are successes, albeit small ones.
They may have more false starts, but I have a feeling they'll eventually both get jobs and be happy, hopefully with a real marriage certificate someday soon. This was just an interesting detour in their lives that the author wanted to draw.
It may have been better if it had ended with a page of them discussing the summer when they're middle-aged and successful, and how wild and misguided it was, but how they were happy they were able to do it.