Named Ser Aylin, the mod in question (via Eurogamer) affects the relationship between Ketheric's daughter Isobel and the aasimar Dame Aylin.
Beware there are some very mild spoilers ahead for some act 2 characters.
Nexus Mods, likely the most popular mod site on the planet and a place you're definitely familiar with if you've ever had cause to tinker with a Bethesda game, has banned a user for attempting to mod a same-sex pairing out of Baldur's Gate 3.
