Favourite relationship development in a series?

One of my favourite parts of same-couple series is seeing their relationship progression and development - how the MCs get through the external struggles together and even the angst certain misunderstandings and discoveries cause.

My favourite series are: - {Valor and Doyle series by Nicky James} - the best part of the series is the way they deal with Aslan's alcoholism together. - {Big Bad Wolf series by Charlie Adhara} - just the way they trusted eachother more and more with each book (and that there was no more miscommunication by the last one 👀) - {Adrien English series by Josh Lanyon} - this is honestly a hit or miss with the sub, but I was rooting for them the whole time - {Soulbound series by Hailey Turner} - Patrick and Jono are honestly just relationship goals. I loved the way they took care of eachother throughout the whole series, and they were honest too.

What are your favourite relationships in same-couple series?