Genesis 26:8

26:8 It happened, when he had been there a long time, that Abimelech king of the Philistines looked out at a window, and saw, and, behold, Isaac was caressing Rebekah, his wife.
-World English Bible

Other Translation

26:8 And it came to pass, when he had been there a long time, that Abimelech king of the Philistines looked out at a window, and saw, and, behold, Isaac [was] sporting with Rebekah his wife.
-King James Version