ISO an ID: Erotic novel about 2 young girls who are best friends go to an island for a vacation and end up having sex with a ton of people there.

In the 80s I owned a few “porn novels” and at one point I lost a couple of them in a move. I don’t remember the names, but I’ll do my best to describe one.

It was the kind of really hardcore “erotic novel” you used to see in the 80s or 90s, with either drawn art or photo covers. Definitely not a “bodice-ripper.”

It was about 2 young girls who are best friends who go to an island (think something like Nantucket – in fact, it may have been that island, I don’t remember) for a vacation (I believe with the parents of one of the girls) and end up having sex with a ton of people on the island, including boys, men and even 1 married couple.

Does anyone know the book I’m describing?