Hi all.
The two possible scenario's I'm looking for are:
1) A main character is introduced to his mothers new boyfriend, this man is manipulative and eventually is getting into the pants of the MC's girlfriend, and possibly sisters, etc.
or
2) A father seduces his son's girlfriend/fiancé/wife whilst the son is away studying/working/deployed.
I don't want to split this down further with more parameters and kinks. At this point in time I'm happy for stories that are 'close enough' to this scenario as I'm not having much luck looking myself.
Thanks,
Ryan