Wow, I stopped by here to find some content (non-adult) and I find this, pretty sad. I agree, was a great trade partner and webmistress. I'm sure you will be missed here.
Sounds pretty much like the same reason, or similar as to why I sold all my adult sites. Some times it just gets old and you don't want to do it any more, I know exactly what that's like. When it turns into "work", it's probably time to leave. Least that was me.
Oddly, as I scan the forum, many sites getting sold huh? Is adult not going well right now, or lately? Obviously I have not been around it in some time.
Sad to see you go, you were one of the best to work with, that's for sure
Best of luck!