User blog comment:Qraanberry/Confused about Triss and Yennefer's relationship?/@comment-26477900-20150623184134/@comment-985084-20150623224814

That depends upon whether you romance Yen or not. If you do the quest "the Last Wish" and tell Yennefer you love her then mention the bed she does not get angry and both agree not to speak of it. It bothers her, but she knows Geralt loves her and not Triss.

Yennefer is one of my favourite characters from the books and more interesting by far than Triss (Yennefer's "dear friend" letter is hilarious) so I always pick her. Also I do try and play in a manner faithful to the books in which Geralt would feel more guilt being with Triss than love.