I realised half way through that I had read Part 1 before - i.e. before I ever watched LoM! And, if you remember, I liked it then. I liked it better now that I know the characters but I still think it stands alone quite well.
I liked Part 2. The subtle changes in the relationship were fascinating. And I'm not usually turned on by bdsm but this was really well done.
Yes, you wrote porn but well written porn becomes erotica, so take heart! You are following in the footsteps of 'classics' like Daniel Defoe, after all. Just because it's m/m instead of f/m is irrelevant!
Also, I wasn't fond of either character in the series but now I think I'll look harder at both of them in season 2.