Recommendations needed: Romance trilogy or series featuring the same couple

I’m working on a historical romance set during the Harlem Renaissance. My original idea was to write a series featuring three different couples. To be honest, I’m still strongly inclined to follow through with that plan.

However, I’m exploring the possibility of going deeper into the story of how these two characters get together. To accomplish that, I considered revealing their love story over a series of three novellas.So, I’d like to read a few romance trilogies or series that feature a sin...