Keira Metz is a sorceress well known to Geralt. In the game you initiate a mandatory contact with her during the search for Ciri in Velen. Ex-member of the Lodge hid herself in a cabin on the sidelines. She helps near villagers in solving their trouble. Geralt learns about her camouflage when in the main storyline he decides to find local witch (Hunting a Witch mission) who is said to be in conflict with Ciri.
Geralt and Keira together start searching for a masked wizard with whom Ciri planned to meet. When they reach elven ruins, suddenly they are attacked by soldiers of the Wild Hunt. Once the witcher defeats one of them in an exhausting battle, the pair can leave the dungeons. However, Metz wants to get another artifact belonging to the previously mentioned wizard and she will ask Geralt for help (Magic Lamp). He must accept that offer.
The search will end with finding the Magic Lamp. The item allows to communicate with the ghosts of the dead people. Keira will take the item but will give Geralt a proposition of another visit (An Invitation from Keira Metz). This will lead to a series of side quests. Now Geralt must go to sorceress home and accept the contract on undoing the curse on an island. (A Towerful of Mise). After he completes the contract, Keira once more will ask witcher for help. This time he must find the transport of commodities from Novigrad which has been lost somewhere along the way. This task (A Favor for a Friend) must be completed as well.
Giving the items to Keira will have some repercussions. Metz will conjure up two beautiful horses, change the clothing of both characters and take Geralt to a special dinner in the forest. After a short conversation and a small game of hide and seek, the sorceress will go to bed with the witcher (only if Geralt will want to, he can refuse the sorceress by telling her that he is a relationship with someone else).
Triss is currently living in Novigrad. Meeting her is a mandatory point of the storyline. The sorceress will mark her presence at various points of the game, not only in the main storyline, but in side quests as well. The latter will lead to an affair with Triss, although the Witcher will have to put some effort and speak the right things to reach a happy ending.
The main condition of luring Triss to bed is helping wizards and other scholars in escaping from Novigrad. This ambitious plan can be started with A Matter of Life and Death quest. When miss Merigold invites Geralt to her quarters, you should go there and do everything the girl asks. The mission objective is to lead the alchemist out of Vegelbunds property. The main action will be done on a mask ball. Proper clothing and well-led dialogues will make Triss drink too much. This will give you the opportunity for the first step - kissing the girl. This chance will be shown as a dialogue option.
Further part of the operation will start after eliminating a brutal thug controlling the local criminal element. When Geralt gets him and participate in mandatory audience at the Redanian king's on the ship (A Favor for Radowid), the messenger will give him a letter. After reading it you can complete the Now or Never quest. In that quest Geralt will help wizards escape to Kovir. First decisions don't matter too much, most important decision can be made after finding the road in the sewers and defeating Katakan vampire. After that battle, all the characters important for that quest will reach the harbor and Triss will start saying goodbye to the witcher.
Rejecting sorceress at that point will end the whole subplot, but if Geralt asks Triss to stay with him in Novigrad, interesting dialogue options will be available. In a limited time, you must show your feelings to the girl ("I love you" or ask her for another chance ("Let's try again"). In a short cutscene after the conversation, the ship will sail to Kovir but Merigold will stay with Geralt. Further conversation won't have any big importance. The two will go to a lighthouse where, after a short conversation, they will spend the night together.
Geralt will have an occasion to sleep with Yennefer at least twice during the game. In both cases it will be a part of the main storyline so you won't be able to miss it. First opportunity shows itself when the pair will be together on Skellige islands (The King is Dead - Long Live the King mission) where the two participate in a wake for the dead leader of warrior clans.
After a short meeting at the table, Yen will encourage the witcher to visit Mousesack chamber and steal the mysterious Mask of Uroboros. Although the task is risky, it must be completed anyway to push the storyline forward. After a battle with the creature protecting the artifact, the woman will want to fix her dress with a magic needle in her chamber. This is when Geralt should act. In a short conversation you must convince Yennefer that the wake can wait. It will lead to some love scenes on a unicorn. Once they satisfy each other, Geralt and Yennefer will return to the wake to complete the rest of the task.
Second scene can be triggered in Kaer Morhen, during the No Place like Home quest. The witchers gathered in the fortress will accept Vesemir's plan to save Uma. To kill some time, they will start drinking alcohol. During this feast, Yennefer will try to lure Geralt to the side and will ask him to come to her chamber. Geralt can refuse and return to his colleagues. If he accepts, the two will have some fun upstairs. After that, Geralt will return to the feast and the quest will continue.
Triss versus Yennefer
After returning from Kaer Morhen to Novigrad and completing all preparations for the final battle with the Wild Hunt (Final Preparations), the game will automatically activate the It Takes Three to Tango quest. If you have had sex with both Triss and Yennefer before, ladies will now offer Geralt a threesome. You must walk down to the base level of the tavern, buy any high quality wine and go to the tavern called Kingfisher. Yennefer and Triss are waiting in one of the apartments on the first floor.
Ladies must have talked behind Geralt back as they know that he has expressed his feelings to both of them. Sorceress' revenge will be rather humiliating. Our hero will allow himself to be handcuffed to the bed and after an encouraging beginning to some love games, left behind by the ladies...