She is stunning
"That dress is simply stunning"
In the <b>sentence</b>, "It was stunning sex." 'stunning' is appropriate but the <b>sentence</b> itself is awkward. A better suited <b>sentence</b> with the same meaning would be, "The sex was stunning."
This is how you use the word "stun" in a sentence.
These fields of flowers are stunning.
Her incomparable skill was stunning.
That bejeweled cumberbund with his tuxedo is just stunning! That tuxedo complements his stunning good looks rather nicely.
the man built a stunning device for the future
My grandfather has many stunning items from 1970's.
To me, the Canyon was a stunning place.
Haley, Claire, and Aqua were all wearing a stunning dress to the last splash In the movie "Aqua Marine."
The mayor and all his associates were voted out of office in a stunning renunciation of his policies.
The ridge of the mountain offered stunning views of the valley below.