I'm trying to ID a 70s science fiction movie involving an AI that takes a woman (I think) hostage. It's not Demon Seed. IIRC it takes place in some slightly futuristic (in a 70s way) accommodation in a hi-tech looking establishment rather than in an automated home like Demon Seed. Another element that differs from Demon Seed is that the husband (I think) of the hostage asks for conjugal rights on the grounds that humans need these to remain healthy. This allows them to plot an escape together.
Doctor Forbin was the name of the primary creator of the giant computer Colossus. Doctor Cleo Markham was another scientist on the project, maybe his second-in-command. After Colossus takes over, Markham acts as Forbin's mistress. I don't recall whether it was an act, or whether they were actually romantically involved (they may have been married between the first book and the sequel).
Forbin, who was under constant surveillance, had convinced Colossus that some privacy was necessary for human beings, so it turns the cameras off while she visits, allowing them to plot against it. I don't think escape was their goal; they were trying to shut down Colossus.