As others have said, I think it is highly likely that this is a mistake. It would be an act of extreme professional stupidity for him to follow those accounts publicly. However, even with that in mind, I would be bothered by seeing this - even an accidental association of my therapist with those images and pornographic exploitation would be deeply unsettling for me. Pornography and the sexual commodification of women is not a neutral area, no matter what sexual liberals would like others to believe