This was the hardest of all the puzzles, though people who found earlier codes harder usually found this one easy, and vice versa.
The five aqua words (got up, understands, reserve, skin + rooms) were meant to be replaced by other words which meant the same thing but also had a second meaning that, in the context of the letter, made sense.
got up = rose = our love has blossomed like a rose
understands = knows = nose = your petit nose (though many people picked 'figure', which I really wish I had used instead)
reserve = book = your angelic face is often hidden behind a book
skin = hide = you cannot hide it from me
rooms = suite = sweet = the whole world will know of our sweet romance.
The initial codes were more maths-based and this one with its synonyms is more linguistic-based (that's why I found this one so hard), and honest-to-god, I thought the final word was "SPACE", and the idea of their "space romance" is forever stuck in my head and makes me giggle at odd hours.