A new book claims that ELIZABETH TAYLOR was intimate with RONALD REAGAN and hooked up with JOHN F. KENNEDY and "Untouchables" star ROBERT STACK, together.

The Reagan thing happened when Liz was just a teenager, and Ronnie was 36.  He invited Liz to his place, but then SHE made the first move.  The book says that Liz told a friend, "Reagan was treating me like a grown woman, and that thrilled me.  We sat on his sofa and I could tell he wanted to get it on but he seemed reluctant to make the first move.  "I became the aggressor.  After a heavy make-out session on the sofa, we went into the bedroom."  (Reagan turned 36 in February of 1947.  That same month, Liz turned 15.  Not cool, Gipper.)

As for the rendezvous that JFK and Robert Stack created, there aren't too many advance details, other than that it happened in JFK's pool.

(The book is called "Elizabeth Taylor:  There Is Nothing Like a Dame", by Danforth Prince and Darwin Potter.  It's due out next week.)