Cold Fish Meaning
(slang) A sexual partner who, during copulation, lacks vigor or emotional reciprocity.
Example: 1610, William Shakespeare, The Winter's Tale, act 4, sc. 4:
[I]t was thought she was a woman and was turned into a cold fish for she would not exchange flesh with one that loved her.
1993, Lisanne Norman, Turning Point:
He wouldn't have thought her such a cold fish. Pity. Still, there was plenty of time. Perhaps when she got used to his company she would thaw a little.
2003, Robert Wilson, The Blind Man of Seville, ISBN 9780156028806, page 13:
You're a cold fish. You have no heart.