Summer School & After School

This book began as a sequel, but the new reader can easily slip into this plot without worrying about knowing who did what to whom before. Since there were some loose ends at the end of the previous book, it seemed useful to provide a continuation. However, to get the whole story, reading 'Summer School' first might be helpful."
In 'Summer School', Lucy von Holt was sent to the Vermont Riding School for pony girl and BDSM training by her boyfriend, Fabian. In After School, Lucy is sent back across the Atlantic to a Cloister School in Bulgaria where the nuns take over where Vermont left off.
In flashbacks, we learn that Lucy's erotic personal history includes some BDSM adventures with Glenda, a gorgeous, wealthy young woman she met in Garmisch. Glenda, who has everything, provides her with more kinky lesbian experience and the two "bond" well in a secluded, high altitude retreat in a snowstorm.