Heinlein's later work

Finished a re-reading of R.A Heinlein’s “The cat who walks through walls”/ Though it is a most excellent sequel to his classic “The Moon is a harsh mistress”, I do not find it an appropriate book to give to a teenager. The latter half of the book is full of sexual innuendo, incest and other odd references to some very peculiar sexual practices. Heinlein in his dotage has written some riveting stories, but the wheat is very much mixed with the chaff in these later tales.