naw just ride on it together. i dont think it breaks. although maybe i just never made it break
whats interesting is that Yen is not really introduced in the game until Witcher 3. Geralt has been looking for her, and has some flashbacks, but he never catches up with her until 3. and then she's all "oh you lost your memory huh, what a lame excuse" and the whole time you were (probably) doing Triss. because of this Yen at some point goes into a jealous fit about red hair in the bed. so later when the player is presented to be between either of them, a video game player would probably take Triss not Yen. well, there's also trying to have both, which makes for an... interesting cut scene