I'm trying to find the name of a book I'd read years ago.  It's a book probably from the 60's, 70's, or maybe 80's, as it was one my parents had.  I remember it was something about this woman and three men, she had invited them to this house or mansion on a private island.  These were all men she'd had relationships with in the past.  It told the story of each of the men's first sexual experiences and I can only vaguely remember two of them.  One had his first encounter as a teenager with a man who was some sort of friend of the family that had taken him on a trip of some sort, so they were in a hotel.  One other had had his first time with a barn animal.  I'm pretty sure it was a horse, but maybe a donkey or cow, don't fully remember.  At the end of the book, I remember the four of them all ended up having "adventures" together by the pool behind the house.  That's about all I remember and I'd love to read that book again, so if anyone recognizes it, I'd love to know the title.  Even if someone gives me a few titles that they think it might be, I might recognize it if I heard it again.  Thanks for any help.