Advice on father-in-law (80) making pornographic photography?

Although I find the images distasteful, that's not what's the real problem. I think he's doing this because he misses the intimacy of a real relationship, his wife died 4 years ago and it's now become an addiction. He's spent thousands on equipment, hiring the models, venues etc. Will not discuss the issue and is angry saying we are 'trying to tell him how to live his life' when we told him we didn't like it. This was after a model nearly died falling into the sea on a 'shoot'. He finds the models on the Internet and invites them into his home and he's taken excess luggage on the airplane for them too. He seems to have lost his sense of 'sensible' risk with anything associated with this. We want to have a good relationship with him but this has become what he describes as his 'life's work' and that he's a serious artist/photographer and we just don't understand.