so it really depends on the client and their reasons for being in therapy!
I personally still don't see how it is appropriate under any context. It wouldn't feel real because we only see them for an hour a week and yes we might be truly ourselves with that t but we can't possibly really know the other to say that.
I personally wouldn't say it to anybody in my life only a significant other.
If a thinks it will help a client and only says it because of that reason they aren't being genuine. Love is such a string word with lots of different meanings to different people.
Here in my country if a therapist said that they would be arrested- I am not criticising anyone's t here but I would not allow mine to say it. I would not accept it.