Georgina Spelvin's the live-in sister of Rhonda Gellard, whose husband Frank Mauro is convinced, after a semi-hot bed session, that she doesn't love him.  Spelvin thinks Mauro loves her, though, and after quickly re-consummating the relationship on his boat, Mauro tries to drop her as well -- so she drops him in the drink, never to be seen again.

That's the set-up for this somewhat depressing sexual romp, as everyone left alive tries to deal with the loss.  This leads Spelvin to a long trip down memory lane with the deceased, including pussy-licking, b.j., cowgirl and mish, plus a possibly imagined encounter in the shower with a comely hiker who wanders into her bathroom (!).  it also leads the family son (Charles Hooper) to peep on neighbor Sharon Thorpe scratching her itch in the living room, and later to mutual masturbation before the fireplace.  It also leads daughter Claire Dia (late of The Cheerleaders) to allow Spelvin to lick her pussy, and later to seduce brother Hooper with 69, mish (shown only in softcore) and a handjob.

There's a bit of worthwhile sexual action here, and in 1975, when the film was made, it was probably pretty racy, but by modern standards, this film just doesn't hold up, despite some decent acting performances.