In "Clan of the Cave Bear" (which I **don't** recommend!) the Cro-Magnon heroine is "pleasured" by a Neanderthal and gives birth to a half-breed. Then she puts two and two together...
and goes on to discover agriculture, tame horses, whatever. (It's a real soap opera)
In the book she is repeatedly raped as a form of humiliation, not pleasured.
Somehow or other, so far I have managed to be spared The Clan of the Cave Bear!
Thanks for writing!