Are there any adults only caravanning sites in peak district (not naturist!) that allows a dog on lead.

Doubt if many will turn away families

Longnor Wood Holiday Park - Derbyshire
This Peak District Holiday Park is a small select park for adults only.
Situated in the Peak National Park, surrounded by woodland and farmland and are perfectly situated for many lovely country walks.
With 47 touring pitches for caravans, motorhomes or tents, as well as 3 holiday homes and 3 lodges available for hire.
Longnor Wood Holiday Park
Longnor
Nr Buxton
Derbyshire
SK17 0NG
Tel :01298 83648
http://www.longnorwood.co.uk/index.html

I'd recommend Longnor Wood, it's a pretty good site.
I don't know if you've used www.ukcampsite.co.uk, but their search facility lets you search for adult only sites in whatever area you want.
PS. I know what you mean about people thinking "adult only" = naturist!!

There is a very comprehensive list of adult only campsites here. (http://www.myfavouritecampsite.com/vB/forumdisplay.php?f=166)
Hope it helps.