Hi! I wonder if there is any mod for romantic interactions with foster (step) siblings? For example, I have a family of a mother and a daughter and the mother has adopted another child. The children are both teenagers now, and I would like to develop their love storyline, but my daughter sim can't make any romantic interactions with her foster brother but "family kiss". Can I change that? Thanks!

This is the section to get help making mods, not finding them. You could try using Sim Blender or something similar to remove the family ties, or do a search for an incest mod (I don't know if one exists, since that's not something that appeals to me).