Good story overall, but there are some issues with spelling (I recognize the British spelling of some words, so I'm not sure if those are considered mis-spellings or correct variants, maybe somebody else can answer that).
I see some incomplete sentences and a need for additional paragraphing. You should consider looking for an editor to help with these 'mechanical' problems.
On the bright side you use good descriptions, so you certainly possess the skills to write.
I have to agree with kbate: eliminating excess adjectives and adverbs andfinding some synonyms for oft-used words would be excellent steps. Passive voice rarely works for erotica, non-erotica, or anything else except academic tracts that are required to be constructed that way.
Still, you're ahead of the curve for a first effort and you're entitled to be proud of your story