I'm always on the lookout for stories that treat relationships with nuance, and when it comes to m/f/m setups that actually model healthy polyamory, I think there are two things to say up front: there aren't as many mainstream examples as people hope for, but some brilliant, compassionate books and indie works do it really well.
One clear published example I turn to is Becky Chambers' 'The Long Way to a Small, Angry Planet' — it isn't a straight romance novel, but the way it presents non‑monogamous and queer relationships feels earned, consensual, and human. If you want fiction that normalizes multiple partners without fetishizing them, places like that are gold. For non‑fiction context that helped me understand healthy structures in real life, I found 'The Argonauts' useful because it explores family, desire, and non‑traditional relationships candidly (it's memoir rather than m/f/m romance, but it sharpened my radar for what feels healthy on the page).
If your goal is strictly romantic escapism in the m/f/m format, a lot of the best portrayals are living in indie romance and fan fiction communities. On platforms like Goodreads, AO3, and even niche Kindle Unlimited lists, search tags such as 'polyamory', 'menage', and 'consent' — those filters will surface stories where communication, boundaries, and negotiated jealousy are emphasized. I also watch for author notes that explicitly say the relationship is poly and consensual; that little transparency usually means the book treats it responsibly. Personally, I love collecting these recs and comparing how different writers handle metamours, jealousy, and legal/social pressures — some lean plot‑heavy, others dwell on the soft, domestic moments, and both can feel healthy when characters grow together rather than being forced into a love triangle.