In the Witcher 3's "Ashen Marriage" quest, set in Novigrad, Geralt assists Triss Merigold and her fiancé, Castello, with wedding preparations. His tasks include monster extermination in the canals, procuring alcohol, and selecting a wedding gift for Triss. The gift's significance impacts Triss's response; a memory rose, a callback to Witcher 2, evokes a strong emotional reaction, unlike more mundane choices.
However, Dijkstra's revelation of Castello's ties to witch hunters throws a wrench into the proceedings. Castello's involvement stems from blackmail – the hunters threaten to expose his daughter from a previous marriage.
Geralt has the option of revealing this truth to Triss, either alone or with Castello. Regardless, the wedding is called off. Triss's reaction varies; she's either disappointed or grateful for Castello's honesty, but ultimately deems the marriage premature.
This unexpected turn could have further developed Geralt and Triss's relationship and provided richer character arcs for supporting characters.