Romance – or perhaps any story – is about the journey, not the destination.
You can make the journey as long as you like but it has to remain interesting – and not repetitive. So long as there is romantic tension there, so long as feelings are building, you can absolutely “go slow”.
But if you’re trying to draw it out, if you’re padding, if you’re getting repetitive, it starts to break the spell.
I had one book where I drew out the relationship by having the hero blow hot and cold probably at least one time too many – and some readers did gripe about it. He had a valid reason for doing so, and there are people who genuinely blow hot and cold non-stop in real life, but it doesn’t necessarily make for the best story. After a while, readers get annoyed.
It’s particularly difficult if you want to write a series about the same couple. I once read a trilogy once where the relationship was clearly dragged out for the sake of being a trilogy. Probably just two books would have sufficed. The same may be true of my Forbidden Love series featuring Laura and Mr Rydell, where I only intended to write one novel. Because I left the ending open I had reader feedback that they wanted a sequel. Somehow that spun out into a three-novel series. Having side-plots has been critical.
If the romance itself is more of a side plot: eg if you’re writing adventure, or fantasy, then it’s much easier to draw it out. For example, Alison Croggan’s The Books of Pellinor tetralogy (four book sequence – though with two prequels added, it’s officially six) is primarily about the heroine’s quest. So while the hero is there from the start, it’s okay that they don’t really get together fully until the very end. Because overall it’s Fantasy not Romance.
So in your situation: what is going on that the readers can be interested in through several books? Ask yourself these questions:
- Do you need to draw out the romance?
- Is it realistic that the couple would take so long to get together?
- What else is going on in the protagonists’ lives?
- Is it an enjoyable and interesting journey for the reader, or is it getting repetitive?
- How can you make each stage new, with different twists and turns and progress?