Hi there! Welcome to the forum.
To answer your question, anything of a sexual nature should be kept to the adult board, that means anything you wouldn't expect to see in a PG-13 movie should be sent to the adult board, keep in mind we have 13 year olds frequenting the site so anything you'd be uncomfortable discussing with them in public shouldn't be posted in the public board and should be reserved for the adult board. (So this includes kink stuff).
That said we do allow talk of a pet/owner relationship, but please keep in mind this should be strictly non-sexual and should be done in the most wholesome of ways. For us, pet & owners behave more on an emotional or fun level, rather than anything adult, so just keep that in mind.
If you have any more questions about what is and isn't allowed on the forum, don't hesitate to PM me or any other moderator, we're always here to help. (And we'd probably prefer questions about sexual stuff to be in PM rather posted too
)